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000
FXUS62 KGSP 261055
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
655 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE OFF THE CAROLINA COAST THIS
MORNING...WITH A TRAILING COLD FRONT PUSHING THROUGH THE FORECAST
AREA. COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL CANADA
LATER TODAY AND WILL REMAIN THE DOMINANT FEATURE FOR THE BEGINNING
OF THE WORK WEEK. ANOTHER AREA OF LOW PRESSURE WILL MOVE EAST FROM
TEXAS TOWARD THE MIDDLE OF THE WEEK AND BRING MORE RAIN WEDNESDAY
AND THURSDAY...WITH A DRYING TREND FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 650 AM...THE WEDGE BOUNDARY HAS SLIDE SW ALONG I-85 OVER THE
PAST THE COUPLE HOURS. THE PLACEMENT OF THE BOUNDARY WILL LIKELY
PLAY A KEY ROLE IN SFC CONVERGENCE AND CONVECTION EARLY THIS
AFTERNOON. THEREFORE...I WILL UPDATE THE FORECAST TO SHIFT CHC POPS
SW...DISPLACED FROM THE RECENT RUNS OF THE CAMS. OTHERWISE...I WILL
UPDATE SKY AND TEMPS TO ALIGN WITH THE LATEST OBSERVATIONS.

AS OF 330 AM...SATELLITE AND RADAR IMAGES CONTINUES TO SHOW THE OLD
MCS ASHING OUT ACROSS THE WESTERN CAROLINAS. LATEST RUN OF THE CAMS
INDICATE THE COVERAGE WILL SPREAD EAST...GRADUALLY FADING TO CHC TO
SCHC. IS WAS INTERESTING TO SEE A SPLITTING CELL ACROSS CHESTERFIELD
CO AT 730Z. AT THE SFC...THE WEDGE FRONT RUNS FROM THE NORTHERN TIP
OF LAKE WATEREE...WEST ACROSS THE GSP METRO AREA...NORTH ALONG THE
EAST FACING SLOPES ACROSS THE NC FOOTHILLS. NORTH OF THE
BOUNDARY...LOW CLOUDS AND FOG WILL PERSIST THROUGH SUNRISE. LOW
CLOUDS AND FOG WILL DISSIPATE FROM THE SOUTH TO NORTH DURING THE
EARLY DAYLIGHT HOURS. BY MID DAY...THE CENTER OF LOW PRESSURE IS
EXPECTED TO PASS ACROSS THE UPSTATE OF SC...TRACKING EAST. A WEAK
BACKDOOR COLD FRONT WILL SWEEP SOUTH ACROSS THE REGION DURING THE
AFTERNOON. AS THE LOW PASSES...THE ENVIRONMENT BETWEEN I-85 TO I-77
COULD SUPPORT SCT TSRA DURING THE MID TO LATE AFTERNOON...I WILL
FORECAST CHC POPS. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM
AROUND 80 ACROSS THE UPPER SAVANNAH RIVER VALLEY TO THE MID 60S
ACROSS I-40 TO THE MTNS.

TONIGHT...IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL BUILD
ACROSS THE SOUTHERN APPALACHIAN REGION. CONDITIONS ACROSS THE REGION
SHOULD BECOME CLEAR TO MOSTLY CLEAR...WINDS BELOW 5 KTS...WITH
DEWPOINT DEPRESSION GREATER THAN 5 DEGREES. LOW TEMPERATURES SHOULD
FALL CLOSE TO NORMAL...FROM THE LOW 40S WITHIN THE MTN VALLEYS TO
LOW 50S ACROSS THE UPPER SAVANNAH RIVER VALLEY.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...SHORT TERM BEGINS WITH LARGE UPPER CLOSED LOW
SPINNING OVER NEW ENGLAND AND SOUTHEAST CANADA...WITH A REINFORCING
SHORTWAVE PUSHING AROUND THE WESTERN PERIPHERY OF THE TROUGH AT THE
BEGINNING OF THE PERIOD. SURFACE HIGH PRESSURE CENTERED OVER SOUTH
CENTRAL CANADA WILL BE RIDGING INTO THE SOUTHEAST. EXPECT A CLEARING
TREND DURING THE DAY ON MONDAY IN THE WAKE OF THE DRY UPPER TROUGH
AXIS PUSHING THROUGH WITH HIGHS BELOW NORMAL UNDER WEAK DEEP LAYER
CAA. CONTINUED BELOW-NORMAL TEMPERATURES MONDAY NIGHT AND WILL HAVE
TO KEEP AN EYE ON LOWS AT THE HIGHER ELEVATIONS IN CASE FROST MIGHT
BE A CONCERN...ESPECIALLY AS WINDS DIE OFF TOWARD SUNRISE TUESDAY.
THE COOL TEMPERATURES CONTINUE ON TUESDAY EVEN WITH MIDLEVEL RIDGING
BEGINNING TO BUILD IN ACROSS THE AREA.

A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL INDUCE CYCLOGENESIS
ACROSS THE NORTHERN GULF MONDAY NIGHT AND EARLY TUESDAY...SPREADING
MOISTURE INTO THE SOUTHEAST TUESDAY AFTERNOON AND EVENING. HAVE
CONTINUED TREND OF RAMPING UP POPS LATE IN THE DAY ON TUESDAY AS
ISENTROPIC UPGLIDE INCREASES ACROSS THE AREA. ECMWF IS BEGINNING TO
TREND A LITTLE FARTHER NORTH WITH THE SURFACE LOW...MORE INTO
SOUTHERN AND EVEN CENTRAL GEORGIA RATHER THAN REMAINING ALONG THE
FLORIDA PANHANDLE...WHICH MIGHT MEAN AN INCREASE IN QPF. OVERALL
MASS FIELDS NOT TOO DISSIMILAR BUT ENOUGH DIFFERENCES IN THE
DETAILS...ESPECIALLY TIMING AND PLACEMENT OF QPF...TO CONTINUE
BLANKETING THE AREA WITH HIGH CHANCE TO LOW LIKELY POPS AT BEST AS
WE TRANSITION INTO THE EXTENDED.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...CHANCE TO LIKELY POPS /ESPECIALLY FOR SOUTHERN
ZONES/ BEGIN THE PERIOD AS THE AFOREMENTIONED SURFACE LOW WORKS ITS
WAY EAST ACROSS SOUTHERN GEORGIA. WITH WIDESPREAD CLOUDINESS AND
RAIN...NOT TO MENTION DECREASING THICKNESSES PLUS JUST BEING ON THE
COLD SIDE OF THE SURFACE LOW...WE CONTINUE TO ADVERTISE HIGHS ON
WEDNESDAY WELL BELOW SEASONAL NORMALS...IN SOME LOCATIONS 10 DEGREES
OR SO.

MODEL INCONSISTENCIES AND RUN-TO-RUN DISCONTINUITY CONTINUE WITH
THIS SYSTEM AS THE 00Z GUIDANCE HAS ONCE AGAIN SWITCHED...WITH THE
GFS EXITING THE PRECIP FROM THE AREA FASTER THAN THE ECMWF.
CONTINUED THE COMPROMISE TREND...PULLING BACK ON POPS DURING THE DAY
ON THURSDAY. ECMWF WANTS TO BRING ANOTHER SHORTWAVE AROUND THE BASE
OF THE ELONGATED TROUGH THURSDAY NIGHT INTO FRIDAY BUT HAVE NOT
REFLECTED THIS IN THE GRIDS AT THIS TIME...PREFERRING INSTEAD THE
DRIER SOLUTIONS...HOWEVER AS WE MOVE FORWARD THIS MAY NEED TO BE
REEVALUATED. WE SHOULD SEE A DRYING TREND INTO THE WEEKEND WITH
TEMPERATURES TRENDING MORE TOWARDS CLIMATOLOGY BUT CONFIDENCE IN ANY
ONE SOLUTION NOT PARTICULARLY HIGH AT THIS POINT.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM LAKE
WATEREE...NORTHEAST KAND...THEN NORTH ALONG THE EAST FACING SLOPES
ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY WERE OBSERVING
LIFR TO VLIFR CEILINGS WITH POCKETS OF LIFR VIS.
KCLT...KHKY...KGSP...AND KGMU WILL REMAIN WITHIN THE CORRIDOR OF LOW
CEILINGS AND VIS THROUGH THE EARLY DAYLIGHT HOURS...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID TO LATE MORNING...THEN VFR BY MID DAY.
KAVL AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR
MASS...COMBINED WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY
EXPECTED TO REMAIN MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY
SHOULD FEATURE BKN LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT
ACROSS KHKY AND KCLT. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE
NORTH TODAY FOLLOWING A COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON SUNDAY THEN
FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW PRESSURE
SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND THURSDAY.

CONFIDENCE TABLE...

            11-17Z        17-23Z        23-05Z        05-06Z
KCLT       MED   78%     HIGH  81%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       MED   78%     MED   75%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED




000
FXUS62 KGSP 261055
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
655 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE OFF THE CAROLINA COAST THIS
MORNING...WITH A TRAILING COLD FRONT PUSHING THROUGH THE FORECAST
AREA. COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL CANADA
LATER TODAY AND WILL REMAIN THE DOMINANT FEATURE FOR THE BEGINNING
OF THE WORK WEEK. ANOTHER AREA OF LOW PRESSURE WILL MOVE EAST FROM
TEXAS TOWARD THE MIDDLE OF THE WEEK AND BRING MORE RAIN WEDNESDAY
AND THURSDAY...WITH A DRYING TREND FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 650 AM...THE WEDGE BOUNDARY HAS SLIDE SW ALONG I-85 OVER THE
PAST THE COUPLE HOURS. THE PLACEMENT OF THE BOUNDARY WILL LIKELY
PLAY A KEY ROLE IN SFC CONVERGENCE AND CONVECTION EARLY THIS
AFTERNOON. THEREFORE...I WILL UPDATE THE FORECAST TO SHIFT CHC POPS
SW...DISPLACED FROM THE RECENT RUNS OF THE CAMS. OTHERWISE...I WILL
UPDATE SKY AND TEMPS TO ALIGN WITH THE LATEST OBSERVATIONS.

AS OF 330 AM...SATELLITE AND RADAR IMAGES CONTINUES TO SHOW THE OLD
MCS ASHING OUT ACROSS THE WESTERN CAROLINAS. LATEST RUN OF THE CAMS
INDICATE THE COVERAGE WILL SPREAD EAST...GRADUALLY FADING TO CHC TO
SCHC. IS WAS INTERESTING TO SEE A SPLITTING CELL ACROSS CHESTERFIELD
CO AT 730Z. AT THE SFC...THE WEDGE FRONT RUNS FROM THE NORTHERN TIP
OF LAKE WATEREE...WEST ACROSS THE GSP METRO AREA...NORTH ALONG THE
EAST FACING SLOPES ACROSS THE NC FOOTHILLS. NORTH OF THE
BOUNDARY...LOW CLOUDS AND FOG WILL PERSIST THROUGH SUNRISE. LOW
CLOUDS AND FOG WILL DISSIPATE FROM THE SOUTH TO NORTH DURING THE
EARLY DAYLIGHT HOURS. BY MID DAY...THE CENTER OF LOW PRESSURE IS
EXPECTED TO PASS ACROSS THE UPSTATE OF SC...TRACKING EAST. A WEAK
BACKDOOR COLD FRONT WILL SWEEP SOUTH ACROSS THE REGION DURING THE
AFTERNOON. AS THE LOW PASSES...THE ENVIRONMENT BETWEEN I-85 TO I-77
COULD SUPPORT SCT TSRA DURING THE MID TO LATE AFTERNOON...I WILL
FORECAST CHC POPS. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM
AROUND 80 ACROSS THE UPPER SAVANNAH RIVER VALLEY TO THE MID 60S
ACROSS I-40 TO THE MTNS.

TONIGHT...IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL BUILD
ACROSS THE SOUTHERN APPALACHIAN REGION. CONDITIONS ACROSS THE REGION
SHOULD BECOME CLEAR TO MOSTLY CLEAR...WINDS BELOW 5 KTS...WITH
DEWPOINT DEPRESSION GREATER THAN 5 DEGREES. LOW TEMPERATURES SHOULD
FALL CLOSE TO NORMAL...FROM THE LOW 40S WITHIN THE MTN VALLEYS TO
LOW 50S ACROSS THE UPPER SAVANNAH RIVER VALLEY.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...SHORT TERM BEGINS WITH LARGE UPPER CLOSED LOW
SPINNING OVER NEW ENGLAND AND SOUTHEAST CANADA...WITH A REINFORCING
SHORTWAVE PUSHING AROUND THE WESTERN PERIPHERY OF THE TROUGH AT THE
BEGINNING OF THE PERIOD. SURFACE HIGH PRESSURE CENTERED OVER SOUTH
CENTRAL CANADA WILL BE RIDGING INTO THE SOUTHEAST. EXPECT A CLEARING
TREND DURING THE DAY ON MONDAY IN THE WAKE OF THE DRY UPPER TROUGH
AXIS PUSHING THROUGH WITH HIGHS BELOW NORMAL UNDER WEAK DEEP LAYER
CAA. CONTINUED BELOW-NORMAL TEMPERATURES MONDAY NIGHT AND WILL HAVE
TO KEEP AN EYE ON LOWS AT THE HIGHER ELEVATIONS IN CASE FROST MIGHT
BE A CONCERN...ESPECIALLY AS WINDS DIE OFF TOWARD SUNRISE TUESDAY.
THE COOL TEMPERATURES CONTINUE ON TUESDAY EVEN WITH MIDLEVEL RIDGING
BEGINNING TO BUILD IN ACROSS THE AREA.

A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL INDUCE CYCLOGENESIS
ACROSS THE NORTHERN GULF MONDAY NIGHT AND EARLY TUESDAY...SPREADING
MOISTURE INTO THE SOUTHEAST TUESDAY AFTERNOON AND EVENING. HAVE
CONTINUED TREND OF RAMPING UP POPS LATE IN THE DAY ON TUESDAY AS
ISENTROPIC UPGLIDE INCREASES ACROSS THE AREA. ECMWF IS BEGINNING TO
TREND A LITTLE FARTHER NORTH WITH THE SURFACE LOW...MORE INTO
SOUTHERN AND EVEN CENTRAL GEORGIA RATHER THAN REMAINING ALONG THE
FLORIDA PANHANDLE...WHICH MIGHT MEAN AN INCREASE IN QPF. OVERALL
MASS FIELDS NOT TOO DISSIMILAR BUT ENOUGH DIFFERENCES IN THE
DETAILS...ESPECIALLY TIMING AND PLACEMENT OF QPF...TO CONTINUE
BLANKETING THE AREA WITH HIGH CHANCE TO LOW LIKELY POPS AT BEST AS
WE TRANSITION INTO THE EXTENDED.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...CHANCE TO LIKELY POPS /ESPECIALLY FOR SOUTHERN
ZONES/ BEGIN THE PERIOD AS THE AFOREMENTIONED SURFACE LOW WORKS ITS
WAY EAST ACROSS SOUTHERN GEORGIA. WITH WIDESPREAD CLOUDINESS AND
RAIN...NOT TO MENTION DECREASING THICKNESSES PLUS JUST BEING ON THE
COLD SIDE OF THE SURFACE LOW...WE CONTINUE TO ADVERTISE HIGHS ON
WEDNESDAY WELL BELOW SEASONAL NORMALS...IN SOME LOCATIONS 10 DEGREES
OR SO.

MODEL INCONSISTENCIES AND RUN-TO-RUN DISCONTINUITY CONTINUE WITH
THIS SYSTEM AS THE 00Z GUIDANCE HAS ONCE AGAIN SWITCHED...WITH THE
GFS EXITING THE PRECIP FROM THE AREA FASTER THAN THE ECMWF.
CONTINUED THE COMPROMISE TREND...PULLING BACK ON POPS DURING THE DAY
ON THURSDAY. ECMWF WANTS TO BRING ANOTHER SHORTWAVE AROUND THE BASE
OF THE ELONGATED TROUGH THURSDAY NIGHT INTO FRIDAY BUT HAVE NOT
REFLECTED THIS IN THE GRIDS AT THIS TIME...PREFERRING INSTEAD THE
DRIER SOLUTIONS...HOWEVER AS WE MOVE FORWARD THIS MAY NEED TO BE
REEVALUATED. WE SHOULD SEE A DRYING TREND INTO THE WEEKEND WITH
TEMPERATURES TRENDING MORE TOWARDS CLIMATOLOGY BUT CONFIDENCE IN ANY
ONE SOLUTION NOT PARTICULARLY HIGH AT THIS POINT.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM LAKE
WATEREE...NORTHEAST KAND...THEN NORTH ALONG THE EAST FACING SLOPES
ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY WERE OBSERVING
LIFR TO VLIFR CEILINGS WITH POCKETS OF LIFR VIS.
KCLT...KHKY...KGSP...AND KGMU WILL REMAIN WITHIN THE CORRIDOR OF LOW
CEILINGS AND VIS THROUGH THE EARLY DAYLIGHT HOURS...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID TO LATE MORNING...THEN VFR BY MID DAY.
KAVL AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR
MASS...COMBINED WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY
EXPECTED TO REMAIN MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY
SHOULD FEATURE BKN LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT
ACROSS KHKY AND KCLT. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE
NORTH TODAY FOLLOWING A COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON SUNDAY THEN
FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW PRESSURE
SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND THURSDAY.

CONFIDENCE TABLE...

            11-17Z        17-23Z        23-05Z        05-06Z
KCLT       MED   78%     HIGH  81%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       MED   78%     MED   75%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED


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000
FXUS62 KCHS 260832
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
432 AM EDT SUN APR 26 2015

.SYNOPSIS...
A BACKDOOR COLD FRONT WILL APPROACH FROM THE NORTH TODAY THEN DROP
ACROSS THE AREA THIS EVENING INTO THE EARLY OVERNIGHT HOURS. DRY
HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY. A GULF OF MEXICO
STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH DRY HIGH
PRESSURE EVENTUALLY RETURNING LATER THIS WEEK AND LASTING THROUGH
THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...THE SHORT WAVE TROUGH RESPONSIBLE FOR THE
QUASI-LINEAR CONVECTIVE SYSTEM /QLCS/ THAT MOVED THROUGH LAST
EVENING CONTINUES TO SHIFT WELL OUT INTO THE OPEN
ATLANTIC...LEAVING SUBSIDENCE BEHIND IT ITS WAKE. LINGERING LOW
LEVEL MOISTURE TRAPPED BENEATH THE RESULTING SUBSIDENCE
INVERSION...AIDED BY MOIST GROUND CONDITIONS FROM HEAVY RAINFALL
YESTERDAY...SHOULD RESULT IN THE DEVELOPMENT OF SOME LOW STRATUS
AROUND DAYBREAK. OTHERWISE...TEMPERATURES WILL REMAIN NEARLY
STEADY THROUGH DAYBREAK.

TODAY AND THIS EVENING...A DEEP/STRONG WESTERLY FLOW WILL PREVAIL
INTO THIS AFTERNOON AHEAD OF A SOUTHWARD ADVANCING BACKDOOR COLD
FRONT. THIS BACKDOOR COLD FRONT IS FORECAST TO DROP SOUTH INTO
NORTHERN PORTIONS OF THE CHARLESTON TRI-COUNTY AREA AFTER 4
PM...THEN CONTINUE TO SHIFT ACROSS THE REMAINDER OF THE AREA
DURING THE EVENING AS AN UPPER LEVEL TROUGH BUILDS DOWN THE
EASTERN SEABOARD.

GIVEN THE DRY WESTERLY FLOW...DEEP MOISTURE WILL BE LACKING AHEAD
OF THE FRONT TODAY. HOWEVER...MOST OF THE MODELS INCLUDING NEARLY
ALL OF THE HIGH RESOLUTION MESOSCALE MODELS DEPICT ISOLATED TO
EVEN SCATTERED CONVECTION DEVELOPING LATE THIS AFTERNOON AND
PERSISTING THROUGH THE EVENING IN ASSOCIATION WITH LOW LEVEL
CONVERGENCE IN THE VICINITY OF THE BACKDOOR COLD FRONT. THE
FORECAST THEREFORE INDICATES 20-30 PERCENT RAIN CHANCES MAINLY
NORTH OF AN ALLENDALE...HAMPTON...YEMASSEE...DALE LINE. WHILE
SURFACE BASED INSTABILITY IS LIMITED...WITH SBCAPE VALUES ONLY
AROUND 500 J/KG...SOME OF THE THUNDERSTORMS COULD STILL BECOME
STRONG IF NOT MARGINALLY SEVERE WITH SOME ORGANIZATION POSSIBLE
ALONG/AHEAD OF THE FRONT GIVEN EFFECTIVE BULK SHEAR VALUES AROUND
60 KT. DOWNDRAFT CAPE VALUES UPWARDS OF 1200-1400 J/KG WILL BE
SUPPORTIVE OF DAMAGING WINDS GUSTS WHILE RELATIVELY LOW WET BULB
ZERO HEIGHTS COULD SUPPORT LARGE HAIL FORMATION. GIVEN THESE
CONDITIONS...WILL ADD MENTION OF THE POTENTIAL FOR SEVERE WEATHER
IN THE HAZARDOUS WEATHER OUTLOOK WHERE THUNDERSTORMS ARE FORECAST.

PERHAPS THE BIGGEST STORY TODAY WILL BE THE HOT TEMPERATURES. THE
WARM DOWNSLOPE FLOW COMBINED WITH STRONG COMPRESSIONAL HEATING
AHEAD OF THE FRONT WILL LIKELY PUSH TEMPERATURES TO HIGHS AROUND
90 ACROSS MOST AREAS. THE SEA BREEZE WILL REMAIN PINNED NEAR THE
BEACHES/BARRIER ISLANDS THIS AFTERNOON...THUS LITTLE RELIEF IS
EXPECTED EVEN JUST INLAND FROM THE COAST. THESE TEMPERATURES COULD
EVEN BE A BIT CONSERVATIVE IF THE DEVELOPMENT OF ANY SIGNIFICANT
CLOUD COVER HOLDS OFF UNTIL AFTER PEAK HEATING. MODELS TEND TO
BE TOO COOL IN THESE SCENARIOS...AND DO NOT SEEM TO PROPERLY
ACCOUNT FOR THE FULL INFLUENCE OF STRONG DOWNSLOPE WINDS AND
COMPRESSIONAL HEATING.

OVERNIGHT...THE BACKDOOR COLD FRONT WILL DROP SOUTH OF THE AREA
DURING THE EARLY OVERNIGHT HOURS...WITH MUCH COOLER/DRIER HIGH
PRESSURE BUILDING INTO THE REGION FROM THE NORTHWEST. LOWS ARE
EXPECTED TO RANGE FROM THE MID AND UPPER 50S ACROSS NORTH AND
NORTHWEST PORTIONS OF THE FORECAST AREA...WITH LOWER 60S CLOSER TO
NORTH COASTAL GEORGIA.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MONDAY...HIGH PRESSURE TO THE NORTHEAST WILL PREVAIL WITH DRY
WEATHER AND TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID
70S. COULD SEE SOME UPPER 40S MONDAY NIGHT...MAINLY OVER INTERIOR
SOUTHEAST SC WHERE THE BEST RADIATIONAL COOLING IS EXPECTED.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE LIGHT SHOWERS SOUTH OF I-16 BUT MOST AREAS SHOULD REMAIN DRY
GIVEN THE LINGERING LOW-LEVEL DRY AIR IN PLACE. TEMPERATURES WILL BE
COOLER THAN MONDAY GIVEN THE INCREASED CLOUD COVER...PROBABLY MORE
LIKE 70-74. RAIN CHANCES WILL INCREASE TUESDAY NIGHT AS DEEP
MOISTURE MOVES INTO THE AREA AHEAD OF THE APPROACHING LOW PRESSURE
SYSTEM AND DEVELOPING WARM FRONT AROUND THE FLORIDA
PANHANDLE/SOUTHERN GEORGIA. SOME OF THE RAIN COULD BE HEAVY AT TIMES
BUT CHANCES FOR THUNDER WILL BE LOW AND MAINLY LATE AS IT WILL TAKE
A WHILE FOR SUFFICIENT INSTABILITY TO DEVELOP.

WEDNESDAY...PROBABLY THE WORST...OR AT LEAST THE WETTEST...WEATHER
OF THE WEEK AS LOW PRESSURE MOVES THROUGH SOUTHEAST GEORGIA BRINGING
WIDESPREAD MODERATE TO OCCASIONALLY HEAVY RAINFALL. BEST CHANCE FOR
THUNDERSTORMS WILL BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTHERN
SC COAST. COULD EVEN SOME STRONGER T-STORMS IF THE WARM FRONT CAN
MAKE IT INTO THE AREA AND ALLOW FOR SUFFICIENT INSTABILITY GIVEN
PLENTY OF DEEP LAYER SHEAR IN PLACE. TEMPS WILL BE HIGHLY DEPENDENT
ON THE TRACK OF THE LOW AND WARM FRONT WITH A BIG SPREAD POSSIBLE
FROM NORTHWEST /MID TO UPPER 60S/ TO SOUTHEAST LOWER TO MID 70S/.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
A BIT BETTER MODEL AGREEMENT NOW REGARDING THE LOW PRESSURE SYSTEM
MOVING UP THE SOUTHEAST COAST WEDNESDAY NIGHT...ALTHOUGH THE ECMWF
CONTINUES TO BE SLOWER AND STRONGER THAN THE GFS. EITHER WAY IT
LOOKS LIKE RAIN CHANCES WILL BE DIMINISHING FROM SOUTHWEST TO
NORTHEAST WITH THE BEST CHANCES OVER SOUTHERN SOUTH CAROLINA. CANNOT
RULE OUT SOME LINGERING SHOWERS THURSDAY/FRIDAY AS THE UPPER LOW IS
SLOW TO MOVE THROUGH WITH TEMPS REMAINING BELOW NORMAL IN THE 70S.
IT LOOKS DRY FOR SATURDAY THROUGH SUNDAY LOOK DRIER AS HIGH PRESSURE
RETURNS WITH TEMPS GETTING BACK TO NEAR OR JUST ABOVE NORMAL.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
LOW STRATUS COULD DEVELOP AROUND DAYBREAK AT THE TERMINALS DUE TO
LINGERING LOW LEVEL MOISTURE...WET GROUND CONDITIONS AND A
SUBSIDENCE INVERSION...POSSIBLY RESULTING IN MVFR OR LOWER
CONDITIONS FOR A FEW HOURS. OTHERWISE...VFR CONDITIONS ARE
EXPECTED TO PREVAIL. A POTENT 35-40 KT LOW LEVEL JET AT 2K FT WILL
RESULT IN SOME LOW WIND SHEAR AT THE TERMINALS THROUGH ABOUT
1330Z. ONCE THE INVERSION LIFTS AND MIXING COMMENCES IN THE
MORNING...THE STRONGER WINDS ALOFT WILL MIX DOWN IN THE FORM OF
HIGHER GUSTS...WHICH COULD PEAK UPWARDS OF 25-30 KT IN THE
AFTERNOON WHEN THE DEEPEST MIXING WILL OCCUR. A BACKDOOR COLD
FRONT WILL DROP IN FROM THE NORTH THIS EVENING...AND COULD PRODUCE
SOME ISOLATED SHOWERS AND THUNDERSTORMS AROUND KCHS IN THE 22-03Z
TIME FRAME...AND VICINITY THUNDERSTORMS HAVE BEEN ADDED TO THE TAF
ACCORDINGLY.

EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL MON INTO
TUE BEFORE SHOWERS AND POSSIBLY A FEW TSTMS RETURN LATER TUE AND
ESPECIALLY TUE NIGHT INTO WED NIGHT. SOME OF THE RAIN WILL BE
MODERATE TO HEAVY SO IFR OR LOWER CONDS ARE LIKELY DURING THIS
TIME. VFR SHOULD PREVAIL THU/FRI.

&&

.MARINE...
TODAY...A STRONG LOW LEVEL JET WILL KEEP WINDS/SEAS ELEVATED THIS
MORNING...WITH A SMALL CRAFT ADVISORY CONTINUING IN THE OUTER
GEORGIA WATERS UNTIL 11 AM THIS MORNING. WINDS WILL BACK MORE TO
THE SOUTHWEST THIS AFTERNOON AND DIMINISH IN SPEED A BIT AHEAD OF
A BACKDOOR COLD FRONT APPROACHING FROM THE NORTH. SEAS WILL
GENERALLY RANGE FROM 2-4 FT GIVEN A LIMITED FETCH.

TONIGHT...A BACKDOOR COLD FRONT WILL DROP THROUGH THE WATERS THIS
EVENING INTO THE EARLY OVERNIGHT HOURS...CAUSING WINDS TO VEER
NORTH-NORTHEAST AND INCREASE IN SPEED UPWARDS OF 15-20 KT AS THE
GRADIENT TIGHTENS AND A COOLER AIRMASS SPREADS INTO THE AREA AS
HIGH PRESSURE BUILDS FROM THE NORTHWEST. COULD NOT RULE OUT SMALL
CRAFT ADVISORY CONDITIONS DEVELOPING...BUT AT THIS TIME MODEL
CONSENSUS KEEPS WINDS JUST BELOW CRITERIA.

MONDAY THROUGH FRIDAY...HIGH PRESSURE BUILDING FROM THE NORTH SHOULD
LEAD TO A WEAKENING PRESSURE GRADIENT AND THUS WINDS AS WELL INTO
MONDAY NIGHT BEFORE CONDITIONS GO BACK DOWNHILL AS DEVELOPING LOW
PRESSURE APPROACHES FROM THE SOUTHWEST TUESDAY/WEDNESDAY BEFORE
PASSING THROUGH THE AREA WEDNESDAY NIGHT. BEST SHOT AT SMALL CRAFT
ADVISORIES WILL BE BEYOND 20 NM AND OVER THE NEARSHORE WATERS OFF
CHARLESTON COUNTY. EXPECT IMPROVING CONDITIONS THU AND ESPECIALLY BY
FRI.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ374.

&&

$$

NEAR TERM...JAQ
SHORT TERM...RJB
LONG TERM...RJB
AVIATION...JAQ/RJB
MARINE...JAQ/RJB



000
FXUS62 KCHS 260832
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
432 AM EDT SUN APR 26 2015

.SYNOPSIS...
A BACKDOOR COLD FRONT WILL APPROACH FROM THE NORTH TODAY THEN DROP
ACROSS THE AREA THIS EVENING INTO THE EARLY OVERNIGHT HOURS. DRY
HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY. A GULF OF MEXICO
STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH DRY HIGH
PRESSURE EVENTUALLY RETURNING LATER THIS WEEK AND LASTING THROUGH
THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...THE SHORT WAVE TROUGH RESPONSIBLE FOR THE
QUASI-LINEAR CONVECTIVE SYSTEM /QLCS/ THAT MOVED THROUGH LAST
EVENING CONTINUES TO SHIFT WELL OUT INTO THE OPEN
ATLANTIC...LEAVING SUBSIDENCE BEHIND IT ITS WAKE. LINGERING LOW
LEVEL MOISTURE TRAPPED BENEATH THE RESULTING SUBSIDENCE
INVERSION...AIDED BY MOIST GROUND CONDITIONS FROM HEAVY RAINFALL
YESTERDAY...SHOULD RESULT IN THE DEVELOPMENT OF SOME LOW STRATUS
AROUND DAYBREAK. OTHERWISE...TEMPERATURES WILL REMAIN NEARLY
STEADY THROUGH DAYBREAK.

TODAY AND THIS EVENING...A DEEP/STRONG WESTERLY FLOW WILL PREVAIL
INTO THIS AFTERNOON AHEAD OF A SOUTHWARD ADVANCING BACKDOOR COLD
FRONT. THIS BACKDOOR COLD FRONT IS FORECAST TO DROP SOUTH INTO
NORTHERN PORTIONS OF THE CHARLESTON TRI-COUNTY AREA AFTER 4
PM...THEN CONTINUE TO SHIFT ACROSS THE REMAINDER OF THE AREA
DURING THE EVENING AS AN UPPER LEVEL TROUGH BUILDS DOWN THE
EASTERN SEABOARD.

GIVEN THE DRY WESTERLY FLOW...DEEP MOISTURE WILL BE LACKING AHEAD
OF THE FRONT TODAY. HOWEVER...MOST OF THE MODELS INCLUDING NEARLY
ALL OF THE HIGH RESOLUTION MESOSCALE MODELS DEPICT ISOLATED TO
EVEN SCATTERED CONVECTION DEVELOPING LATE THIS AFTERNOON AND
PERSISTING THROUGH THE EVENING IN ASSOCIATION WITH LOW LEVEL
CONVERGENCE IN THE VICINITY OF THE BACKDOOR COLD FRONT. THE
FORECAST THEREFORE INDICATES 20-30 PERCENT RAIN CHANCES MAINLY
NORTH OF AN ALLENDALE...HAMPTON...YEMASSEE...DALE LINE. WHILE
SURFACE BASED INSTABILITY IS LIMITED...WITH SBCAPE VALUES ONLY
AROUND 500 J/KG...SOME OF THE THUNDERSTORMS COULD STILL BECOME
STRONG IF NOT MARGINALLY SEVERE WITH SOME ORGANIZATION POSSIBLE
ALONG/AHEAD OF THE FRONT GIVEN EFFECTIVE BULK SHEAR VALUES AROUND
60 KT. DOWNDRAFT CAPE VALUES UPWARDS OF 1200-1400 J/KG WILL BE
SUPPORTIVE OF DAMAGING WINDS GUSTS WHILE RELATIVELY LOW WET BULB
ZERO HEIGHTS COULD SUPPORT LARGE HAIL FORMATION. GIVEN THESE
CONDITIONS...WILL ADD MENTION OF THE POTENTIAL FOR SEVERE WEATHER
IN THE HAZARDOUS WEATHER OUTLOOK WHERE THUNDERSTORMS ARE FORECAST.

PERHAPS THE BIGGEST STORY TODAY WILL BE THE HOT TEMPERATURES. THE
WARM DOWNSLOPE FLOW COMBINED WITH STRONG COMPRESSIONAL HEATING
AHEAD OF THE FRONT WILL LIKELY PUSH TEMPERATURES TO HIGHS AROUND
90 ACROSS MOST AREAS. THE SEA BREEZE WILL REMAIN PINNED NEAR THE
BEACHES/BARRIER ISLANDS THIS AFTERNOON...THUS LITTLE RELIEF IS
EXPECTED EVEN JUST INLAND FROM THE COAST. THESE TEMPERATURES COULD
EVEN BE A BIT CONSERVATIVE IF THE DEVELOPMENT OF ANY SIGNIFICANT
CLOUD COVER HOLDS OFF UNTIL AFTER PEAK HEATING. MODELS TEND TO
BE TOO COOL IN THESE SCENARIOS...AND DO NOT SEEM TO PROPERLY
ACCOUNT FOR THE FULL INFLUENCE OF STRONG DOWNSLOPE WINDS AND
COMPRESSIONAL HEATING.

OVERNIGHT...THE BACKDOOR COLD FRONT WILL DROP SOUTH OF THE AREA
DURING THE EARLY OVERNIGHT HOURS...WITH MUCH COOLER/DRIER HIGH
PRESSURE BUILDING INTO THE REGION FROM THE NORTHWEST. LOWS ARE
EXPECTED TO RANGE FROM THE MID AND UPPER 50S ACROSS NORTH AND
NORTHWEST PORTIONS OF THE FORECAST AREA...WITH LOWER 60S CLOSER TO
NORTH COASTAL GEORGIA.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MONDAY...HIGH PRESSURE TO THE NORTHEAST WILL PREVAIL WITH DRY
WEATHER AND TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID
70S. COULD SEE SOME UPPER 40S MONDAY NIGHT...MAINLY OVER INTERIOR
SOUTHEAST SC WHERE THE BEST RADIATIONAL COOLING IS EXPECTED.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE LIGHT SHOWERS SOUTH OF I-16 BUT MOST AREAS SHOULD REMAIN DRY
GIVEN THE LINGERING LOW-LEVEL DRY AIR IN PLACE. TEMPERATURES WILL BE
COOLER THAN MONDAY GIVEN THE INCREASED CLOUD COVER...PROBABLY MORE
LIKE 70-74. RAIN CHANCES WILL INCREASE TUESDAY NIGHT AS DEEP
MOISTURE MOVES INTO THE AREA AHEAD OF THE APPROACHING LOW PRESSURE
SYSTEM AND DEVELOPING WARM FRONT AROUND THE FLORIDA
PANHANDLE/SOUTHERN GEORGIA. SOME OF THE RAIN COULD BE HEAVY AT TIMES
BUT CHANCES FOR THUNDER WILL BE LOW AND MAINLY LATE AS IT WILL TAKE
A WHILE FOR SUFFICIENT INSTABILITY TO DEVELOP.

WEDNESDAY...PROBABLY THE WORST...OR AT LEAST THE WETTEST...WEATHER
OF THE WEEK AS LOW PRESSURE MOVES THROUGH SOUTHEAST GEORGIA BRINGING
WIDESPREAD MODERATE TO OCCASIONALLY HEAVY RAINFALL. BEST CHANCE FOR
THUNDERSTORMS WILL BE OVER SOUTHEAST GEORGIA AND ALONG THE SOUTHERN
SC COAST. COULD EVEN SOME STRONGER T-STORMS IF THE WARM FRONT CAN
MAKE IT INTO THE AREA AND ALLOW FOR SUFFICIENT INSTABILITY GIVEN
PLENTY OF DEEP LAYER SHEAR IN PLACE. TEMPS WILL BE HIGHLY DEPENDENT
ON THE TRACK OF THE LOW AND WARM FRONT WITH A BIG SPREAD POSSIBLE
FROM NORTHWEST /MID TO UPPER 60S/ TO SOUTHEAST LOWER TO MID 70S/.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
A BIT BETTER MODEL AGREEMENT NOW REGARDING THE LOW PRESSURE SYSTEM
MOVING UP THE SOUTHEAST COAST WEDNESDAY NIGHT...ALTHOUGH THE ECMWF
CONTINUES TO BE SLOWER AND STRONGER THAN THE GFS. EITHER WAY IT
LOOKS LIKE RAIN CHANCES WILL BE DIMINISHING FROM SOUTHWEST TO
NORTHEAST WITH THE BEST CHANCES OVER SOUTHERN SOUTH CAROLINA. CANNOT
RULE OUT SOME LINGERING SHOWERS THURSDAY/FRIDAY AS THE UPPER LOW IS
SLOW TO MOVE THROUGH WITH TEMPS REMAINING BELOW NORMAL IN THE 70S.
IT LOOKS DRY FOR SATURDAY THROUGH SUNDAY LOOK DRIER AS HIGH PRESSURE
RETURNS WITH TEMPS GETTING BACK TO NEAR OR JUST ABOVE NORMAL.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
LOW STRATUS COULD DEVELOP AROUND DAYBREAK AT THE TERMINALS DUE TO
LINGERING LOW LEVEL MOISTURE...WET GROUND CONDITIONS AND A
SUBSIDENCE INVERSION...POSSIBLY RESULTING IN MVFR OR LOWER
CONDITIONS FOR A FEW HOURS. OTHERWISE...VFR CONDITIONS ARE
EXPECTED TO PREVAIL. A POTENT 35-40 KT LOW LEVEL JET AT 2K FT WILL
RESULT IN SOME LOW WIND SHEAR AT THE TERMINALS THROUGH ABOUT
1330Z. ONCE THE INVERSION LIFTS AND MIXING COMMENCES IN THE
MORNING...THE STRONGER WINDS ALOFT WILL MIX DOWN IN THE FORM OF
HIGHER GUSTS...WHICH COULD PEAK UPWARDS OF 25-30 KT IN THE
AFTERNOON WHEN THE DEEPEST MIXING WILL OCCUR. A BACKDOOR COLD
FRONT WILL DROP IN FROM THE NORTH THIS EVENING...AND COULD PRODUCE
SOME ISOLATED SHOWERS AND THUNDERSTORMS AROUND KCHS IN THE 22-03Z
TIME FRAME...AND VICINITY THUNDERSTORMS HAVE BEEN ADDED TO THE TAF
ACCORDINGLY.

EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL MON INTO
TUE BEFORE SHOWERS AND POSSIBLY A FEW TSTMS RETURN LATER TUE AND
ESPECIALLY TUE NIGHT INTO WED NIGHT. SOME OF THE RAIN WILL BE
MODERATE TO HEAVY SO IFR OR LOWER CONDS ARE LIKELY DURING THIS
TIME. VFR SHOULD PREVAIL THU/FRI.

&&

.MARINE...
TODAY...A STRONG LOW LEVEL JET WILL KEEP WINDS/SEAS ELEVATED THIS
MORNING...WITH A SMALL CRAFT ADVISORY CONTINUING IN THE OUTER
GEORGIA WATERS UNTIL 11 AM THIS MORNING. WINDS WILL BACK MORE TO
THE SOUTHWEST THIS AFTERNOON AND DIMINISH IN SPEED A BIT AHEAD OF
A BACKDOOR COLD FRONT APPROACHING FROM THE NORTH. SEAS WILL
GENERALLY RANGE FROM 2-4 FT GIVEN A LIMITED FETCH.

TONIGHT...A BACKDOOR COLD FRONT WILL DROP THROUGH THE WATERS THIS
EVENING INTO THE EARLY OVERNIGHT HOURS...CAUSING WINDS TO VEER
NORTH-NORTHEAST AND INCREASE IN SPEED UPWARDS OF 15-20 KT AS THE
GRADIENT TIGHTENS AND A COOLER AIRMASS SPREADS INTO THE AREA AS
HIGH PRESSURE BUILDS FROM THE NORTHWEST. COULD NOT RULE OUT SMALL
CRAFT ADVISORY CONDITIONS DEVELOPING...BUT AT THIS TIME MODEL
CONSENSUS KEEPS WINDS JUST BELOW CRITERIA.

MONDAY THROUGH FRIDAY...HIGH PRESSURE BUILDING FROM THE NORTH SHOULD
LEAD TO A WEAKENING PRESSURE GRADIENT AND THUS WINDS AS WELL INTO
MONDAY NIGHT BEFORE CONDITIONS GO BACK DOWNHILL AS DEVELOPING LOW
PRESSURE APPROACHES FROM THE SOUTHWEST TUESDAY/WEDNESDAY BEFORE
PASSING THROUGH THE AREA WEDNESDAY NIGHT. BEST SHOT AT SMALL CRAFT
ADVISORIES WILL BE BEYOND 20 NM AND OVER THE NEARSHORE WATERS OFF
CHARLESTON COUNTY. EXPECT IMPROVING CONDITIONS THU AND ESPECIALLY BY
FRI.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ374.

&&

$$

NEAR TERM...JAQ
SHORT TERM...RJB
LONG TERM...RJB
AVIATION...JAQ/RJB
MARINE...JAQ/RJB



  [top]

000
FXUS62 KCAE 260753
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
353 AM EDT SUN APR 26 2015

.SYNOPSIS...A BACK DOOR COLD FRONT WILL MOVE THROUGH THE REGION
TODAY. DRY COOL HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION
BEHIND THE FRONT FOR SUNDAY NIGHT THROUGH TUESDAY. MOISTURE RETURN
EXPECTED LATE TUESDAY AND WEDNESDAY.

&&

.NEAR TERM /TODAY/...
A GENERAL W TO WNW UPPER FLOW WILL CONTINUE OVER OUR REGION
TODAY. AT THE SURFACE...WEAK IN SITU WEDGE IN PLACE MAINLY TO OUR
NE OVER VA/NC AND INTO OUR EXTREME NE FORECAST AREA (FA). AREAS OF
DENSE FOG WILL BE POSSIBLE OVER OUR NE FA...MAINLY LANCASTER AND
CHESTERFIELD CO...THROUGH THE OVERNIGHT INTO MID SUNDAY MORNING.
WILL HAVE TO MONITOR FOR POSSIBLE DENSE FOG ADVISORY. COLD FRONT
OVER TENN WITH AREA OF LOW PRESSURE ALONG IT. CONVECTIVE ACTIVITY
SHIFTING SE INTO W NC...BUT TREND IS TOWARDS WEAKENING...BUT WILL
MAINTAIN SMALL POP NE FA LATE TONIGHT INTO SUN MORN. AS UPPER
ENERGY MOVES EAST FROM THE OHIO VALLEY INTO THE MID ATLANTIC
TODAY...THE FRONT...AND SURFACE WAVE RIDING ALONG IT...WILL SLOWLY
BACK DOOR TO THE SOUTH ACROSS OUR FA TODAY INTO THIS EVENING. THE
FRONT WILL PROVIDE A FOCUSING MECHANISM FOR AFTERNOON CONVECTION.
CHANCE POPS NEAR THE FRONT...DIURNALLY FAVORED...APPEARS
REASONABLE. SATELLITE WATER VAPOR IMAGERY INDICATES A LARGE
EXPANSE OF DRY AIR ALOFT MOVING INTO THE REGION. MOISTURE IS A
LIMITING FACTOR BUT PWAT VALUES SURGE TO NEAR 1.5 INCHES WITHIN
THE FRONTAL ZONE THIS AFTERNOON. MODELS INDICATING SUFFICIENT
INSTABILITY TODAY ALONG WITH CONSIDERABLE SHEAR. STRONG LOW LEVEL
WIND FIELDS WITH SUFFICIENT SHEAR TO SUPPORT SVR CONVECTION IF
STORMS INITIATE. COLD AIR ALOFT SHOULD LEAD TO STEEP LAPSE RATES
AND MODERATE INSTABILITY. STORM MOTION AROUND 310/30 KNOTS MAY
SUPPORT TRAINING OF STORMS IF THEY DEVELOP. DRY AIR ALOFT WOULD
INCREASE THE POTENTIAL FOR DOWNBURST WINDS AND HAIL WITH ANY
THUNDERSTORMS THAT DO FORM. ISOLATED TORNADO WITH STORMS NEAR THE
FRONTAL ZONE AND ENHANCED HELICITY CANNOT BE RULED OUT. SPC HAS
AREA IN MARGINAL RISK BUT THINK THIS COULD BE UNDERDONE.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
FRONT WILL PUSH TO OUR SOUTH TONIGHT. ANY ASSOCIATED CONVECTION
EXPECTED TO WEAKEN AND/OR PUSH TO OUR SOUTH EARLY TONIGHT. COOL AND
GENERALLY DRY AIR WILL FILTER INTO THE REGION BEHIND THE
FRONT...APPEARING TO PRECLUDE POPS LATE TONIGHT INTO MONDAY.
INCREASING HIGH LEVEL CLOUDINESS AHEAD OF THE NEXT SYSTEM POSSIBLE
BY LATE MON OR MON NT.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
LATEST GFS AND ECMWF IN GOOD AGREEMENT THAT CLOSED UPPER LOW TO
OUR WEST WILL OPEN AND SHIFT EASTWARD...LEADING TO SURFACE LOW
DEVELOPING AND RIDING EAST ALONG THE GULF COAST SPREADING MOISTURE
INTO OUR REGION LATE TUE OR TUE NT THROUGH WED/WED NT. BOTH MODELS
ALSO INDICATE NORTHERN STREAM UPPER LOW DIGGING INTO THE E CONUS
THURSDAY WILL GENERALLY STAY TO OUR NE. HOWEVER...SOME
UNCERTAINTIES EXIST REGARDING TIMING AND POSITION OF THESE
SYSTEMS. WILL MAINTAIN THE SMALL POP THURSDAY. BEHIND THESE
SYSTEMS...A NW UPPER FLOW WILL DIRECT A DRY HIGH PRESSURE CENTER
SE INTO OUR REGION LATE WEEK INTO NEXT WEEKEND.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
EVENING CONVECTION HAS SHIFTED EAST OF THE AREA AND DRIER AIR
ALOFT IS MOVING IN. SURFACE LOW PRESSURE IS MOVING EASTWARD ACROSS
THE NC/VA MOUNTAINS AND WILL CONTINUE TO SHIFT EAST ACROSS NC
THROUGH THE DAY. CURRENT SATELLITE IMAGERY SHOWS WIDESPREAD LIFR
STRATUS/FOG ON THE NORTHSIDE OF A NEARLY STATIONARY FRONT ACROSS
THE NORTHERN MIDLANDS. THIS FRONT AND RESTRICTIONS ARE EXPECTED TO
REMAIN NORTH OF THE TERMINALS OVERNIGHT BUT THERE HAVE BEEN SIGNS
OF POCKETS OF LOW CLOUDS DEVELOPING DUE TO NOCTURNAL COOLING AND
MOS GUIDANCE IS SUGGESTING A PERIOD OF MVFR/IFR CIGS IMPACTING THE
TERMINALS. CONFIDENCE IS LOW IN THE IFR CIGS DEVELOPING BUT WILL
CARRY A PERIOD OF MVFR CIGS 08Z-12Z. STRONG LOW LEVEL JET AROUND
35 KNOTS SHOULD PREVENT/LIMIT FOG DEVELOPMENT ALTHOUGH IT CANNOT
BE RULED OUT.

INCREASING PRESSURE GRADIENT AND STRONG LOW LEVEL WIND FIELD WILL
ALLOW STRONG MIXING TO OCCUR DURING THE DAY TODAY AND EXPECT
BREEZY WESTERLY WINDS AROUND 15 KNOTS WITH GUSTS AROUND 25 KNOTS.
STRONG INSTABILITY THIS AFTERNOON BUT LIMITED MOISTURE PRECLUDES
ANY MENTION OF TSRA IN THIS FORECAST THOUGH THERE IS REASON TO
BELIEVE ISOLATED TO SCATTERED STORMS MAY DEVELOP WITH DIURNAL
HEATING.


EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KCAE 260753
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
353 AM EDT SUN APR 26 2015

.SYNOPSIS...A BACK DOOR COLD FRONT WILL MOVE THROUGH THE REGION
TODAY. DRY COOL HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION
BEHIND THE FRONT FOR SUNDAY NIGHT THROUGH TUESDAY. MOISTURE RETURN
EXPECTED LATE TUESDAY AND WEDNESDAY.

&&

.NEAR TERM /TODAY/...
A GENERAL W TO WNW UPPER FLOW WILL CONTINUE OVER OUR REGION
TODAY. AT THE SURFACE...WEAK IN SITU WEDGE IN PLACE MAINLY TO OUR
NE OVER VA/NC AND INTO OUR EXTREME NE FORECAST AREA (FA). AREAS OF
DENSE FOG WILL BE POSSIBLE OVER OUR NE FA...MAINLY LANCASTER AND
CHESTERFIELD CO...THROUGH THE OVERNIGHT INTO MID SUNDAY MORNING.
WILL HAVE TO MONITOR FOR POSSIBLE DENSE FOG ADVISORY. COLD FRONT
OVER TENN WITH AREA OF LOW PRESSURE ALONG IT. CONVECTIVE ACTIVITY
SHIFTING SE INTO W NC...BUT TREND IS TOWARDS WEAKENING...BUT WILL
MAINTAIN SMALL POP NE FA LATE TONIGHT INTO SUN MORN. AS UPPER
ENERGY MOVES EAST FROM THE OHIO VALLEY INTO THE MID ATLANTIC
TODAY...THE FRONT...AND SURFACE WAVE RIDING ALONG IT...WILL SLOWLY
BACK DOOR TO THE SOUTH ACROSS OUR FA TODAY INTO THIS EVENING. THE
FRONT WILL PROVIDE A FOCUSING MECHANISM FOR AFTERNOON CONVECTION.
CHANCE POPS NEAR THE FRONT...DIURNALLY FAVORED...APPEARS
REASONABLE. SATELLITE WATER VAPOR IMAGERY INDICATES A LARGE
EXPANSE OF DRY AIR ALOFT MOVING INTO THE REGION. MOISTURE IS A
LIMITING FACTOR BUT PWAT VALUES SURGE TO NEAR 1.5 INCHES WITHIN
THE FRONTAL ZONE THIS AFTERNOON. MODELS INDICATING SUFFICIENT
INSTABILITY TODAY ALONG WITH CONSIDERABLE SHEAR. STRONG LOW LEVEL
WIND FIELDS WITH SUFFICIENT SHEAR TO SUPPORT SVR CONVECTION IF
STORMS INITIATE. COLD AIR ALOFT SHOULD LEAD TO STEEP LAPSE RATES
AND MODERATE INSTABILITY. STORM MOTION AROUND 310/30 KNOTS MAY
SUPPORT TRAINING OF STORMS IF THEY DEVELOP. DRY AIR ALOFT WOULD
INCREASE THE POTENTIAL FOR DOWNBURST WINDS AND HAIL WITH ANY
THUNDERSTORMS THAT DO FORM. ISOLATED TORNADO WITH STORMS NEAR THE
FRONTAL ZONE AND ENHANCED HELICITY CANNOT BE RULED OUT. SPC HAS
AREA IN MARGINAL RISK BUT THINK THIS COULD BE UNDERDONE.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
FRONT WILL PUSH TO OUR SOUTH TONIGHT. ANY ASSOCIATED CONVECTION
EXPECTED TO WEAKEN AND/OR PUSH TO OUR SOUTH EARLY TONIGHT. COOL AND
GENERALLY DRY AIR WILL FILTER INTO THE REGION BEHIND THE
FRONT...APPEARING TO PRECLUDE POPS LATE TONIGHT INTO MONDAY.
INCREASING HIGH LEVEL CLOUDINESS AHEAD OF THE NEXT SYSTEM POSSIBLE
BY LATE MON OR MON NT.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
LATEST GFS AND ECMWF IN GOOD AGREEMENT THAT CLOSED UPPER LOW TO
OUR WEST WILL OPEN AND SHIFT EASTWARD...LEADING TO SURFACE LOW
DEVELOPING AND RIDING EAST ALONG THE GULF COAST SPREADING MOISTURE
INTO OUR REGION LATE TUE OR TUE NT THROUGH WED/WED NT. BOTH MODELS
ALSO INDICATE NORTHERN STREAM UPPER LOW DIGGING INTO THE E CONUS
THURSDAY WILL GENERALLY STAY TO OUR NE. HOWEVER...SOME
UNCERTAINTIES EXIST REGARDING TIMING AND POSITION OF THESE
SYSTEMS. WILL MAINTAIN THE SMALL POP THURSDAY. BEHIND THESE
SYSTEMS...A NW UPPER FLOW WILL DIRECT A DRY HIGH PRESSURE CENTER
SE INTO OUR REGION LATE WEEK INTO NEXT WEEKEND.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
EVENING CONVECTION HAS SHIFTED EAST OF THE AREA AND DRIER AIR
ALOFT IS MOVING IN. SURFACE LOW PRESSURE IS MOVING EASTWARD ACROSS
THE NC/VA MOUNTAINS AND WILL CONTINUE TO SHIFT EAST ACROSS NC
THROUGH THE DAY. CURRENT SATELLITE IMAGERY SHOWS WIDESPREAD LIFR
STRATUS/FOG ON THE NORTHSIDE OF A NEARLY STATIONARY FRONT ACROSS
THE NORTHERN MIDLANDS. THIS FRONT AND RESTRICTIONS ARE EXPECTED TO
REMAIN NORTH OF THE TERMINALS OVERNIGHT BUT THERE HAVE BEEN SIGNS
OF POCKETS OF LOW CLOUDS DEVELOPING DUE TO NOCTURNAL COOLING AND
MOS GUIDANCE IS SUGGESTING A PERIOD OF MVFR/IFR CIGS IMPACTING THE
TERMINALS. CONFIDENCE IS LOW IN THE IFR CIGS DEVELOPING BUT WILL
CARRY A PERIOD OF MVFR CIGS 08Z-12Z. STRONG LOW LEVEL JET AROUND
35 KNOTS SHOULD PREVENT/LIMIT FOG DEVELOPMENT ALTHOUGH IT CANNOT
BE RULED OUT.

INCREASING PRESSURE GRADIENT AND STRONG LOW LEVEL WIND FIELD WILL
ALLOW STRONG MIXING TO OCCUR DURING THE DAY TODAY AND EXPECT
BREEZY WESTERLY WINDS AROUND 15 KNOTS WITH GUSTS AROUND 25 KNOTS.
STRONG INSTABILITY THIS AFTERNOON BUT LIMITED MOISTURE PRECLUDES
ANY MENTION OF TSRA IN THIS FORECAST THOUGH THERE IS REASON TO
BELIEVE ISOLATED TO SCATTERED STORMS MAY DEVELOP WITH DIURNAL
HEATING.


EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCAE 260753
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
353 AM EDT SUN APR 26 2015

.SYNOPSIS...A BACK DOOR COLD FRONT WILL MOVE THROUGH THE REGION
TODAY. DRY COOL HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION
BEHIND THE FRONT FOR SUNDAY NIGHT THROUGH TUESDAY. MOISTURE RETURN
EXPECTED LATE TUESDAY AND WEDNESDAY.

&&

.NEAR TERM /TODAY/...
A GENERAL W TO WNW UPPER FLOW WILL CONTINUE OVER OUR REGION
TODAY. AT THE SURFACE...WEAK IN SITU WEDGE IN PLACE MAINLY TO OUR
NE OVER VA/NC AND INTO OUR EXTREME NE FORECAST AREA (FA). AREAS OF
DENSE FOG WILL BE POSSIBLE OVER OUR NE FA...MAINLY LANCASTER AND
CHESTERFIELD CO...THROUGH THE OVERNIGHT INTO MID SUNDAY MORNING.
WILL HAVE TO MONITOR FOR POSSIBLE DENSE FOG ADVISORY. COLD FRONT
OVER TENN WITH AREA OF LOW PRESSURE ALONG IT. CONVECTIVE ACTIVITY
SHIFTING SE INTO W NC...BUT TREND IS TOWARDS WEAKENING...BUT WILL
MAINTAIN SMALL POP NE FA LATE TONIGHT INTO SUN MORN. AS UPPER
ENERGY MOVES EAST FROM THE OHIO VALLEY INTO THE MID ATLANTIC
TODAY...THE FRONT...AND SURFACE WAVE RIDING ALONG IT...WILL SLOWLY
BACK DOOR TO THE SOUTH ACROSS OUR FA TODAY INTO THIS EVENING. THE
FRONT WILL PROVIDE A FOCUSING MECHANISM FOR AFTERNOON CONVECTION.
CHANCE POPS NEAR THE FRONT...DIURNALLY FAVORED...APPEARS
REASONABLE. SATELLITE WATER VAPOR IMAGERY INDICATES A LARGE
EXPANSE OF DRY AIR ALOFT MOVING INTO THE REGION. MOISTURE IS A
LIMITING FACTOR BUT PWAT VALUES SURGE TO NEAR 1.5 INCHES WITHIN
THE FRONTAL ZONE THIS AFTERNOON. MODELS INDICATING SUFFICIENT
INSTABILITY TODAY ALONG WITH CONSIDERABLE SHEAR. STRONG LOW LEVEL
WIND FIELDS WITH SUFFICIENT SHEAR TO SUPPORT SVR CONVECTION IF
STORMS INITIATE. COLD AIR ALOFT SHOULD LEAD TO STEEP LAPSE RATES
AND MODERATE INSTABILITY. STORM MOTION AROUND 310/30 KNOTS MAY
SUPPORT TRAINING OF STORMS IF THEY DEVELOP. DRY AIR ALOFT WOULD
INCREASE THE POTENTIAL FOR DOWNBURST WINDS AND HAIL WITH ANY
THUNDERSTORMS THAT DO FORM. ISOLATED TORNADO WITH STORMS NEAR THE
FRONTAL ZONE AND ENHANCED HELICITY CANNOT BE RULED OUT. SPC HAS
AREA IN MARGINAL RISK BUT THINK THIS COULD BE UNDERDONE.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
FRONT WILL PUSH TO OUR SOUTH TONIGHT. ANY ASSOCIATED CONVECTION
EXPECTED TO WEAKEN AND/OR PUSH TO OUR SOUTH EARLY TONIGHT. COOL AND
GENERALLY DRY AIR WILL FILTER INTO THE REGION BEHIND THE
FRONT...APPEARING TO PRECLUDE POPS LATE TONIGHT INTO MONDAY.
INCREASING HIGH LEVEL CLOUDINESS AHEAD OF THE NEXT SYSTEM POSSIBLE
BY LATE MON OR MON NT.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
LATEST GFS AND ECMWF IN GOOD AGREEMENT THAT CLOSED UPPER LOW TO
OUR WEST WILL OPEN AND SHIFT EASTWARD...LEADING TO SURFACE LOW
DEVELOPING AND RIDING EAST ALONG THE GULF COAST SPREADING MOISTURE
INTO OUR REGION LATE TUE OR TUE NT THROUGH WED/WED NT. BOTH MODELS
ALSO INDICATE NORTHERN STREAM UPPER LOW DIGGING INTO THE E CONUS
THURSDAY WILL GENERALLY STAY TO OUR NE. HOWEVER...SOME
UNCERTAINTIES EXIST REGARDING TIMING AND POSITION OF THESE
SYSTEMS. WILL MAINTAIN THE SMALL POP THURSDAY. BEHIND THESE
SYSTEMS...A NW UPPER FLOW WILL DIRECT A DRY HIGH PRESSURE CENTER
SE INTO OUR REGION LATE WEEK INTO NEXT WEEKEND.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
EVENING CONVECTION HAS SHIFTED EAST OF THE AREA AND DRIER AIR
ALOFT IS MOVING IN. SURFACE LOW PRESSURE IS MOVING EASTWARD ACROSS
THE NC/VA MOUNTAINS AND WILL CONTINUE TO SHIFT EAST ACROSS NC
THROUGH THE DAY. CURRENT SATELLITE IMAGERY SHOWS WIDESPREAD LIFR
STRATUS/FOG ON THE NORTHSIDE OF A NEARLY STATIONARY FRONT ACROSS
THE NORTHERN MIDLANDS. THIS FRONT AND RESTRICTIONS ARE EXPECTED TO
REMAIN NORTH OF THE TERMINALS OVERNIGHT BUT THERE HAVE BEEN SIGNS
OF POCKETS OF LOW CLOUDS DEVELOPING DUE TO NOCTURNAL COOLING AND
MOS GUIDANCE IS SUGGESTING A PERIOD OF MVFR/IFR CIGS IMPACTING THE
TERMINALS. CONFIDENCE IS LOW IN THE IFR CIGS DEVELOPING BUT WILL
CARRY A PERIOD OF MVFR CIGS 08Z-12Z. STRONG LOW LEVEL JET AROUND
35 KNOTS SHOULD PREVENT/LIMIT FOG DEVELOPMENT ALTHOUGH IT CANNOT
BE RULED OUT.

INCREASING PRESSURE GRADIENT AND STRONG LOW LEVEL WIND FIELD WILL
ALLOW STRONG MIXING TO OCCUR DURING THE DAY TODAY AND EXPECT
BREEZY WESTERLY WINDS AROUND 15 KNOTS WITH GUSTS AROUND 25 KNOTS.
STRONG INSTABILITY THIS AFTERNOON BUT LIMITED MOISTURE PRECLUDES
ANY MENTION OF TSRA IN THIS FORECAST THOUGH THERE IS REASON TO
BELIEVE ISOLATED TO SCATTERED STORMS MAY DEVELOP WITH DIURNAL
HEATING.


EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KCAE 260753
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
353 AM EDT SUN APR 26 2015

.SYNOPSIS...A BACK DOOR COLD FRONT WILL MOVE THROUGH THE REGION
TODAY. DRY COOL HIGH PRESSURE WILL BUILD SOUTH INTO THE REGION
BEHIND THE FRONT FOR SUNDAY NIGHT THROUGH TUESDAY. MOISTURE RETURN
EXPECTED LATE TUESDAY AND WEDNESDAY.

&&

.NEAR TERM /TODAY/...
A GENERAL W TO WNW UPPER FLOW WILL CONTINUE OVER OUR REGION
TODAY. AT THE SURFACE...WEAK IN SITU WEDGE IN PLACE MAINLY TO OUR
NE OVER VA/NC AND INTO OUR EXTREME NE FORECAST AREA (FA). AREAS OF
DENSE FOG WILL BE POSSIBLE OVER OUR NE FA...MAINLY LANCASTER AND
CHESTERFIELD CO...THROUGH THE OVERNIGHT INTO MID SUNDAY MORNING.
WILL HAVE TO MONITOR FOR POSSIBLE DENSE FOG ADVISORY. COLD FRONT
OVER TENN WITH AREA OF LOW PRESSURE ALONG IT. CONVECTIVE ACTIVITY
SHIFTING SE INTO W NC...BUT TREND IS TOWARDS WEAKENING...BUT WILL
MAINTAIN SMALL POP NE FA LATE TONIGHT INTO SUN MORN. AS UPPER
ENERGY MOVES EAST FROM THE OHIO VALLEY INTO THE MID ATLANTIC
TODAY...THE FRONT...AND SURFACE WAVE RIDING ALONG IT...WILL SLOWLY
BACK DOOR TO THE SOUTH ACROSS OUR FA TODAY INTO THIS EVENING. THE
FRONT WILL PROVIDE A FOCUSING MECHANISM FOR AFTERNOON CONVECTION.
CHANCE POPS NEAR THE FRONT...DIURNALLY FAVORED...APPEARS
REASONABLE. SATELLITE WATER VAPOR IMAGERY INDICATES A LARGE
EXPANSE OF DRY AIR ALOFT MOVING INTO THE REGION. MOISTURE IS A
LIMITING FACTOR BUT PWAT VALUES SURGE TO NEAR 1.5 INCHES WITHIN
THE FRONTAL ZONE THIS AFTERNOON. MODELS INDICATING SUFFICIENT
INSTABILITY TODAY ALONG WITH CONSIDERABLE SHEAR. STRONG LOW LEVEL
WIND FIELDS WITH SUFFICIENT SHEAR TO SUPPORT SVR CONVECTION IF
STORMS INITIATE. COLD AIR ALOFT SHOULD LEAD TO STEEP LAPSE RATES
AND MODERATE INSTABILITY. STORM MOTION AROUND 310/30 KNOTS MAY
SUPPORT TRAINING OF STORMS IF THEY DEVELOP. DRY AIR ALOFT WOULD
INCREASE THE POTENTIAL FOR DOWNBURST WINDS AND HAIL WITH ANY
THUNDERSTORMS THAT DO FORM. ISOLATED TORNADO WITH STORMS NEAR THE
FRONTAL ZONE AND ENHANCED HELICITY CANNOT BE RULED OUT. SPC HAS
AREA IN MARGINAL RISK BUT THINK THIS COULD BE UNDERDONE.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
FRONT WILL PUSH TO OUR SOUTH TONIGHT. ANY ASSOCIATED CONVECTION
EXPECTED TO WEAKEN AND/OR PUSH TO OUR SOUTH EARLY TONIGHT. COOL AND
GENERALLY DRY AIR WILL FILTER INTO THE REGION BEHIND THE
FRONT...APPEARING TO PRECLUDE POPS LATE TONIGHT INTO MONDAY.
INCREASING HIGH LEVEL CLOUDINESS AHEAD OF THE NEXT SYSTEM POSSIBLE
BY LATE MON OR MON NT.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
LATEST GFS AND ECMWF IN GOOD AGREEMENT THAT CLOSED UPPER LOW TO
OUR WEST WILL OPEN AND SHIFT EASTWARD...LEADING TO SURFACE LOW
DEVELOPING AND RIDING EAST ALONG THE GULF COAST SPREADING MOISTURE
INTO OUR REGION LATE TUE OR TUE NT THROUGH WED/WED NT. BOTH MODELS
ALSO INDICATE NORTHERN STREAM UPPER LOW DIGGING INTO THE E CONUS
THURSDAY WILL GENERALLY STAY TO OUR NE. HOWEVER...SOME
UNCERTAINTIES EXIST REGARDING TIMING AND POSITION OF THESE
SYSTEMS. WILL MAINTAIN THE SMALL POP THURSDAY. BEHIND THESE
SYSTEMS...A NW UPPER FLOW WILL DIRECT A DRY HIGH PRESSURE CENTER
SE INTO OUR REGION LATE WEEK INTO NEXT WEEKEND.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
EVENING CONVECTION HAS SHIFTED EAST OF THE AREA AND DRIER AIR
ALOFT IS MOVING IN. SURFACE LOW PRESSURE IS MOVING EASTWARD ACROSS
THE NC/VA MOUNTAINS AND WILL CONTINUE TO SHIFT EAST ACROSS NC
THROUGH THE DAY. CURRENT SATELLITE IMAGERY SHOWS WIDESPREAD LIFR
STRATUS/FOG ON THE NORTHSIDE OF A NEARLY STATIONARY FRONT ACROSS
THE NORTHERN MIDLANDS. THIS FRONT AND RESTRICTIONS ARE EXPECTED TO
REMAIN NORTH OF THE TERMINALS OVERNIGHT BUT THERE HAVE BEEN SIGNS
OF POCKETS OF LOW CLOUDS DEVELOPING DUE TO NOCTURNAL COOLING AND
MOS GUIDANCE IS SUGGESTING A PERIOD OF MVFR/IFR CIGS IMPACTING THE
TERMINALS. CONFIDENCE IS LOW IN THE IFR CIGS DEVELOPING BUT WILL
CARRY A PERIOD OF MVFR CIGS 08Z-12Z. STRONG LOW LEVEL JET AROUND
35 KNOTS SHOULD PREVENT/LIMIT FOG DEVELOPMENT ALTHOUGH IT CANNOT
BE RULED OUT.

INCREASING PRESSURE GRADIENT AND STRONG LOW LEVEL WIND FIELD WILL
ALLOW STRONG MIXING TO OCCUR DURING THE DAY TODAY AND EXPECT
BREEZY WESTERLY WINDS AROUND 15 KNOTS WITH GUSTS AROUND 25 KNOTS.
STRONG INSTABILITY THIS AFTERNOON BUT LIMITED MOISTURE PRECLUDES
ANY MENTION OF TSRA IN THIS FORECAST THOUGH THERE IS REASON TO
BELIEVE ISOLATED TO SCATTERED STORMS MAY DEVELOP WITH DIURNAL
HEATING.


EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KGSP 260750
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
350 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE OFF THE CAROLINA COAST THIS
MORNING...WITH A TRAILING COLD FRONT PUSHING THROUGH THE FORECAST
AREA. COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL CANADA
LATER TODAY AND WILL REMAIN THE DOMINANT FEATURE FOR THE BEGINNING
OF THE WORK WEEK. ANOTHER AREA OF LOW PRESSURE WILL MOVE EAST FROM
TEXAS TOWARD THE MIDDLE OF THE WEEK AND BRING MORE RAIN WEDNESDAY
AND THURSDAY...WITH A DRYING TREND FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM...SATELLITE AND RADAR IMAGES CONTINUES TO SHOW THE OLD
MCS ASHING OUT ACROSS THE WESTERN CAROLINAS. LATEST RUN OF THE CAMS
INDICATE THE COVERAGE WILL SPREAD EAST...GRADUALLY FADING TO CHC TO
SCHC. IS WAS INTERESTING TO SEE A SPLITTING CELL ACROSS CHESTERFIELD
CO AT 730Z. AT THE SFC...THE WEDGE FRONT RUNS FROM THE NORTHERN TIP
OF LAKE WATEREE...WEST ACROSS THE GSP METRO AREA...NORTH ALONG THE
EAST FACING SLOPES ACROSS THE NC FOOTHILLS. NORTH OF THE
BOUNDARY...LOW CLOUDS AND FOG WILL PERSIST THROUGH SUNRISE. LOW
CLOUDS AND FOG WILL DISSIPATE FROM THE SOUTH TO NORTH DURING THE
EARLY DAYLIGHT HOURS. BY MID DAY...THE CENTER OF LOW PRESSURE IS
EXPECTED TO PASS ACROSS THE UPSTATE OF SC...TRACKING EAST. A WEAK
BACKDOOR COLD FRONT WILL SWEEP SOUTH ACROSS THE REGION DURING THE
AFTERNOON. AS THE LOW PASSES...THE ENVIRONMENT BETWEEN I-85 TO I-77
COULD SUPPORT SCT TSRA DURING THE MID TO LATE AFTERNOON...I WILL
FORECAST CHC POPS. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM
AROUND 80 ACROSS THE UPPER SAVANNAH RIVER VALLEY TO THE MID 60S
ACROSS I-40 TO THE MTNS.

TONIGHT...IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL BUILD
ACROSS THE SOUTHERN APPALACHIAN REGION. CONDITIONS ACROSS THE REGION
SHOULD BECOME CLEAR TO MOSTLY CLEAR...WINDS BELOW 5 KTS...WITH
DEWPOINT DEPRESSION GREATER THAN 5 DEGREES. LOW TEMPERATURES SHOULD
FALL CLOSE TO NORMAL...FROM THE LOW 40S WITHIN THE MTN VALLEYS TO
LOW 50S ACROSS THE UPPER SAVANNAH RIVER VALLEY.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...SHORT TERM BEGINS WITH LARGE UPPER CLOSED LOW
SPINNING OVER NEW ENGLAND AND SOUTHEAST CANADA...WITH A REINFORCING
SHORTWAVE PUSHING AROUND THE WESTERN PERIPHERY OF THE TROUGH AT THE
BEGINNING OF THE PERIOD. SURFACE HIGH PRESSURE CENTERED OVER SOUTH
CENTRAL CANADA WILL BE RIDGING INTO THE SOUTHEAST. EXPECT A CLEARING
TREND DURING THE DAY ON MONDAY IN THE WAKE OF THE DRY UPPER TROUGH
AXIS PUSHING THROUGH WITH HIGHS BELOW NORMAL UNDER WEAK DEEP LAYER
CAA. CONTINUED BELOW-NORMAL TEMPERATURES MONDAY NIGHT AND WILL HAVE
TO KEEP AN EYE ON LOWS AT THE HIGHER ELEVATIONS IN CASE FROST MIGHT
BE A CONCERN...ESPECIALLY AS WINDS DIE OFF TOWARD SUNRISE TUESDAY.
THE COOL TEMPERATURES CONTINUE ON TUESDAY EVEN WITH MIDLEVEL RIDGING
BEGINNING TO BUILD IN ACROSS THE AREA.

A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL INDUCE CYCLOGENESIS
ACROSS THE NORTHERN GULF MONDAY NIGHT AND EARLY TUESDAY...SPREADING
MOISTURE INTO THE SOUTHEAST TUESDAY AFTERNOON AND EVENING. HAVE
CONTINUED TREND OF RAMPING UP POPS LATE IN THE DAY ON TUESDAY AS
ISENTROPIC UPGLIDE INCREASES ACROSS THE AREA. ECMWF IS BEGINNING TO
TREND A LITTLE FARTHER NORTH WITH THE SURFACE LOW...MORE INTO
SOUTHERN AND EVEN CENTRAL GEORGIA RATHER THAN REMAINING ALONG THE
FLORIDA PANHANDLE...WHICH MIGHT MEAN AN INCREASE IN QPF. OVERALL
MASS FIELDS NOT TOO DISSIMILAR BUT ENOUGH DIFFERENCES IN THE
DETAILS...ESPECIALLY TIMING AND PLACEMENT OF QPF...TO CONTINUE
BLANKETING THE AREA WITH HIGH CHANCE TO LOW LIKELY POPS AT BEST AS
WE TRANSITION INTO THE EXTENDED.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...CHANCE TO LIKELY POPS /ESPECIALLY FOR SOUTHERN
ZONES/ BEGIN THE PERIOD AS THE AFOREMENTIONED SURFACE LOW WORKS ITS
WAY EAST ACROSS SOUTHERN GEORGIA. WITH WIDESPREAD CLOUDINESS AND
RAIN...NOT TO MENTION DECREASING THICKNESSES PLUS JUST BEING ON THE
COLD SIDE OF THE SURFACE LOW...WE CONTINUE TO ADVERTISE HIGHS ON
WEDNESDAY WELL BELOW SEASONAL NORMALS...IN SOME LOCATIONS 10 DEGREES
OR SO.

MODEL INCONSISTENCIES AND RUN-TO-RUN DISCONTINUITY CONTINUE WITH
THIS SYSTEM AS THE 00Z GUIDANCE HAS ONCE AGAIN SWITCHED...WITH THE
GFS EXITING THE PRECIP FROM THE AREA FASTER THAN THE ECMWF.
CONTINUED THE COMPROMISE TREND...PULLING BACK ON POPS DURING THE DAY
ON THURSDAY. ECMWF WANTS TO BRING ANOTHER SHORTWAVE AROUND THE BASE
OF THE ELONGATED TROUGH THURSDAY NIGHT INTO FRIDAY BUT HAVE NOT
REFLECTED THIS IN THE GRIDS AT THIS TIME...PREFERRING INSTEAD THE
DRIER SOLUTIONS...HOWEVER AS WE MOVE FORWARD THIS MAY NEED TO BE
REEVALUATED. WE SHOULD SEE A DRYING TREND INTO THE WEEKEND WITH
TEMPERATURES TRENDING MORE TOWARDS CLIMATOLOGY BUT CONFIDENCE IN ANY
ONE SOLUTION NOT PARTICULARLY HIGH AT THIS POINT.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       MED   72%     HIGH  84%     HIGH  97%     MED   64%
KGSP       MED   78%     HIGH  96%     HIGH 100%     HIGH 100%
KAVL       HIGH  90%     HIGH  97%     HIGH  95%     MED   78%
KHKY       MED   67%     HIGH  82%     HIGH  90%     HIGH 100%
KGMU       MED   78%     HIGH  96%     HIGH 100%     HIGH 100%
KAND       MED   79%     HIGH 100%     HIGH  91%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED



000
FXUS62 KGSP 260750
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
350 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE OFF THE CAROLINA COAST THIS
MORNING...WITH A TRAILING COLD FRONT PUSHING THROUGH THE FORECAST
AREA. COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL CANADA
LATER TODAY AND WILL REMAIN THE DOMINANT FEATURE FOR THE BEGINNING
OF THE WORK WEEK. ANOTHER AREA OF LOW PRESSURE WILL MOVE EAST FROM
TEXAS TOWARD THE MIDDLE OF THE WEEK AND BRING MORE RAIN WEDNESDAY
AND THURSDAY...WITH A DRYING TREND FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM...SATELLITE AND RADAR IMAGES CONTINUES TO SHOW THE OLD
MCS ASHING OUT ACROSS THE WESTERN CAROLINAS. LATEST RUN OF THE CAMS
INDICATE THE COVERAGE WILL SPREAD EAST...GRADUALLY FADING TO CHC TO
SCHC. IS WAS INTERESTING TO SEE A SPLITTING CELL ACROSS CHESTERFIELD
CO AT 730Z. AT THE SFC...THE WEDGE FRONT RUNS FROM THE NORTHERN TIP
OF LAKE WATEREE...WEST ACROSS THE GSP METRO AREA...NORTH ALONG THE
EAST FACING SLOPES ACROSS THE NC FOOTHILLS. NORTH OF THE
BOUNDARY...LOW CLOUDS AND FOG WILL PERSIST THROUGH SUNRISE. LOW
CLOUDS AND FOG WILL DISSIPATE FROM THE SOUTH TO NORTH DURING THE
EARLY DAYLIGHT HOURS. BY MID DAY...THE CENTER OF LOW PRESSURE IS
EXPECTED TO PASS ACROSS THE UPSTATE OF SC...TRACKING EAST. A WEAK
BACKDOOR COLD FRONT WILL SWEEP SOUTH ACROSS THE REGION DURING THE
AFTERNOON. AS THE LOW PASSES...THE ENVIRONMENT BETWEEN I-85 TO I-77
COULD SUPPORT SCT TSRA DURING THE MID TO LATE AFTERNOON...I WILL
FORECAST CHC POPS. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM
AROUND 80 ACROSS THE UPPER SAVANNAH RIVER VALLEY TO THE MID 60S
ACROSS I-40 TO THE MTNS.

TONIGHT...IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL BUILD
ACROSS THE SOUTHERN APPALACHIAN REGION. CONDITIONS ACROSS THE REGION
SHOULD BECOME CLEAR TO MOSTLY CLEAR...WINDS BELOW 5 KTS...WITH
DEWPOINT DEPRESSION GREATER THAN 5 DEGREES. LOW TEMPERATURES SHOULD
FALL CLOSE TO NORMAL...FROM THE LOW 40S WITHIN THE MTN VALLEYS TO
LOW 50S ACROSS THE UPPER SAVANNAH RIVER VALLEY.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...SHORT TERM BEGINS WITH LARGE UPPER CLOSED LOW
SPINNING OVER NEW ENGLAND AND SOUTHEAST CANADA...WITH A REINFORCING
SHORTWAVE PUSHING AROUND THE WESTERN PERIPHERY OF THE TROUGH AT THE
BEGINNING OF THE PERIOD. SURFACE HIGH PRESSURE CENTERED OVER SOUTH
CENTRAL CANADA WILL BE RIDGING INTO THE SOUTHEAST. EXPECT A CLEARING
TREND DURING THE DAY ON MONDAY IN THE WAKE OF THE DRY UPPER TROUGH
AXIS PUSHING THROUGH WITH HIGHS BELOW NORMAL UNDER WEAK DEEP LAYER
CAA. CONTINUED BELOW-NORMAL TEMPERATURES MONDAY NIGHT AND WILL HAVE
TO KEEP AN EYE ON LOWS AT THE HIGHER ELEVATIONS IN CASE FROST MIGHT
BE A CONCERN...ESPECIALLY AS WINDS DIE OFF TOWARD SUNRISE TUESDAY.
THE COOL TEMPERATURES CONTINUE ON TUESDAY EVEN WITH MIDLEVEL RIDGING
BEGINNING TO BUILD IN ACROSS THE AREA.

A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL INDUCE CYCLOGENESIS
ACROSS THE NORTHERN GULF MONDAY NIGHT AND EARLY TUESDAY...SPREADING
MOISTURE INTO THE SOUTHEAST TUESDAY AFTERNOON AND EVENING. HAVE
CONTINUED TREND OF RAMPING UP POPS LATE IN THE DAY ON TUESDAY AS
ISENTROPIC UPGLIDE INCREASES ACROSS THE AREA. ECMWF IS BEGINNING TO
TREND A LITTLE FARTHER NORTH WITH THE SURFACE LOW...MORE INTO
SOUTHERN AND EVEN CENTRAL GEORGIA RATHER THAN REMAINING ALONG THE
FLORIDA PANHANDLE...WHICH MIGHT MEAN AN INCREASE IN QPF. OVERALL
MASS FIELDS NOT TOO DISSIMILAR BUT ENOUGH DIFFERENCES IN THE
DETAILS...ESPECIALLY TIMING AND PLACEMENT OF QPF...TO CONTINUE
BLANKETING THE AREA WITH HIGH CHANCE TO LOW LIKELY POPS AT BEST AS
WE TRANSITION INTO THE EXTENDED.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...CHANCE TO LIKELY POPS /ESPECIALLY FOR SOUTHERN
ZONES/ BEGIN THE PERIOD AS THE AFOREMENTIONED SURFACE LOW WORKS ITS
WAY EAST ACROSS SOUTHERN GEORGIA. WITH WIDESPREAD CLOUDINESS AND
RAIN...NOT TO MENTION DECREASING THICKNESSES PLUS JUST BEING ON THE
COLD SIDE OF THE SURFACE LOW...WE CONTINUE TO ADVERTISE HIGHS ON
WEDNESDAY WELL BELOW SEASONAL NORMALS...IN SOME LOCATIONS 10 DEGREES
OR SO.

MODEL INCONSISTENCIES AND RUN-TO-RUN DISCONTINUITY CONTINUE WITH
THIS SYSTEM AS THE 00Z GUIDANCE HAS ONCE AGAIN SWITCHED...WITH THE
GFS EXITING THE PRECIP FROM THE AREA FASTER THAN THE ECMWF.
CONTINUED THE COMPROMISE TREND...PULLING BACK ON POPS DURING THE DAY
ON THURSDAY. ECMWF WANTS TO BRING ANOTHER SHORTWAVE AROUND THE BASE
OF THE ELONGATED TROUGH THURSDAY NIGHT INTO FRIDAY BUT HAVE NOT
REFLECTED THIS IN THE GRIDS AT THIS TIME...PREFERRING INSTEAD THE
DRIER SOLUTIONS...HOWEVER AS WE MOVE FORWARD THIS MAY NEED TO BE
REEVALUATED. WE SHOULD SEE A DRYING TREND INTO THE WEEKEND WITH
TEMPERATURES TRENDING MORE TOWARDS CLIMATOLOGY BUT CONFIDENCE IN ANY
ONE SOLUTION NOT PARTICULARLY HIGH AT THIS POINT.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       MED   72%     HIGH  84%     HIGH  97%     MED   64%
KGSP       MED   78%     HIGH  96%     HIGH 100%     HIGH 100%
KAVL       HIGH  90%     HIGH  97%     HIGH  95%     MED   78%
KHKY       MED   67%     HIGH  82%     HIGH  90%     HIGH 100%
KGMU       MED   78%     HIGH  96%     HIGH 100%     HIGH 100%
KAND       MED   79%     HIGH 100%     HIGH  91%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED



000
FXUS62 KGSP 260750
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
350 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE OFF THE CAROLINA COAST THIS
MORNING...WITH A TRAILING COLD FRONT PUSHING THROUGH THE FORECAST
AREA. COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL CANADA
LATER TODAY AND WILL REMAIN THE DOMINANT FEATURE FOR THE BEGINNING
OF THE WORK WEEK. ANOTHER AREA OF LOW PRESSURE WILL MOVE EAST FROM
TEXAS TOWARD THE MIDDLE OF THE WEEK AND BRING MORE RAIN WEDNESDAY
AND THURSDAY...WITH A DRYING TREND FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM...SATELLITE AND RADAR IMAGES CONTINUES TO SHOW THE OLD
MCS ASHING OUT ACROSS THE WESTERN CAROLINAS. LATEST RUN OF THE CAMS
INDICATE THE COVERAGE WILL SPREAD EAST...GRADUALLY FADING TO CHC TO
SCHC. IS WAS INTERESTING TO SEE A SPLITTING CELL ACROSS CHESTERFIELD
CO AT 730Z. AT THE SFC...THE WEDGE FRONT RUNS FROM THE NORTHERN TIP
OF LAKE WATEREE...WEST ACROSS THE GSP METRO AREA...NORTH ALONG THE
EAST FACING SLOPES ACROSS THE NC FOOTHILLS. NORTH OF THE
BOUNDARY...LOW CLOUDS AND FOG WILL PERSIST THROUGH SUNRISE. LOW
CLOUDS AND FOG WILL DISSIPATE FROM THE SOUTH TO NORTH DURING THE
EARLY DAYLIGHT HOURS. BY MID DAY...THE CENTER OF LOW PRESSURE IS
EXPECTED TO PASS ACROSS THE UPSTATE OF SC...TRACKING EAST. A WEAK
BACKDOOR COLD FRONT WILL SWEEP SOUTH ACROSS THE REGION DURING THE
AFTERNOON. AS THE LOW PASSES...THE ENVIRONMENT BETWEEN I-85 TO I-77
COULD SUPPORT SCT TSRA DURING THE MID TO LATE AFTERNOON...I WILL
FORECAST CHC POPS. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM
AROUND 80 ACROSS THE UPPER SAVANNAH RIVER VALLEY TO THE MID 60S
ACROSS I-40 TO THE MTNS.

TONIGHT...IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL BUILD
ACROSS THE SOUTHERN APPALACHIAN REGION. CONDITIONS ACROSS THE REGION
SHOULD BECOME CLEAR TO MOSTLY CLEAR...WINDS BELOW 5 KTS...WITH
DEWPOINT DEPRESSION GREATER THAN 5 DEGREES. LOW TEMPERATURES SHOULD
FALL CLOSE TO NORMAL...FROM THE LOW 40S WITHIN THE MTN VALLEYS TO
LOW 50S ACROSS THE UPPER SAVANNAH RIVER VALLEY.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...SHORT TERM BEGINS WITH LARGE UPPER CLOSED LOW
SPINNING OVER NEW ENGLAND AND SOUTHEAST CANADA...WITH A REINFORCING
SHORTWAVE PUSHING AROUND THE WESTERN PERIPHERY OF THE TROUGH AT THE
BEGINNING OF THE PERIOD. SURFACE HIGH PRESSURE CENTERED OVER SOUTH
CENTRAL CANADA WILL BE RIDGING INTO THE SOUTHEAST. EXPECT A CLEARING
TREND DURING THE DAY ON MONDAY IN THE WAKE OF THE DRY UPPER TROUGH
AXIS PUSHING THROUGH WITH HIGHS BELOW NORMAL UNDER WEAK DEEP LAYER
CAA. CONTINUED BELOW-NORMAL TEMPERATURES MONDAY NIGHT AND WILL HAVE
TO KEEP AN EYE ON LOWS AT THE HIGHER ELEVATIONS IN CASE FROST MIGHT
BE A CONCERN...ESPECIALLY AS WINDS DIE OFF TOWARD SUNRISE TUESDAY.
THE COOL TEMPERATURES CONTINUE ON TUESDAY EVEN WITH MIDLEVEL RIDGING
BEGINNING TO BUILD IN ACROSS THE AREA.

A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL INDUCE CYCLOGENESIS
ACROSS THE NORTHERN GULF MONDAY NIGHT AND EARLY TUESDAY...SPREADING
MOISTURE INTO THE SOUTHEAST TUESDAY AFTERNOON AND EVENING. HAVE
CONTINUED TREND OF RAMPING UP POPS LATE IN THE DAY ON TUESDAY AS
ISENTROPIC UPGLIDE INCREASES ACROSS THE AREA. ECMWF IS BEGINNING TO
TREND A LITTLE FARTHER NORTH WITH THE SURFACE LOW...MORE INTO
SOUTHERN AND EVEN CENTRAL GEORGIA RATHER THAN REMAINING ALONG THE
FLORIDA PANHANDLE...WHICH MIGHT MEAN AN INCREASE IN QPF. OVERALL
MASS FIELDS NOT TOO DISSIMILAR BUT ENOUGH DIFFERENCES IN THE
DETAILS...ESPECIALLY TIMING AND PLACEMENT OF QPF...TO CONTINUE
BLANKETING THE AREA WITH HIGH CHANCE TO LOW LIKELY POPS AT BEST AS
WE TRANSITION INTO THE EXTENDED.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...CHANCE TO LIKELY POPS /ESPECIALLY FOR SOUTHERN
ZONES/ BEGIN THE PERIOD AS THE AFOREMENTIONED SURFACE LOW WORKS ITS
WAY EAST ACROSS SOUTHERN GEORGIA. WITH WIDESPREAD CLOUDINESS AND
RAIN...NOT TO MENTION DECREASING THICKNESSES PLUS JUST BEING ON THE
COLD SIDE OF THE SURFACE LOW...WE CONTINUE TO ADVERTISE HIGHS ON
WEDNESDAY WELL BELOW SEASONAL NORMALS...IN SOME LOCATIONS 10 DEGREES
OR SO.

MODEL INCONSISTENCIES AND RUN-TO-RUN DISCONTINUITY CONTINUE WITH
THIS SYSTEM AS THE 00Z GUIDANCE HAS ONCE AGAIN SWITCHED...WITH THE
GFS EXITING THE PRECIP FROM THE AREA FASTER THAN THE ECMWF.
CONTINUED THE COMPROMISE TREND...PULLING BACK ON POPS DURING THE DAY
ON THURSDAY. ECMWF WANTS TO BRING ANOTHER SHORTWAVE AROUND THE BASE
OF THE ELONGATED TROUGH THURSDAY NIGHT INTO FRIDAY BUT HAVE NOT
REFLECTED THIS IN THE GRIDS AT THIS TIME...PREFERRING INSTEAD THE
DRIER SOLUTIONS...HOWEVER AS WE MOVE FORWARD THIS MAY NEED TO BE
REEVALUATED. WE SHOULD SEE A DRYING TREND INTO THE WEEKEND WITH
TEMPERATURES TRENDING MORE TOWARDS CLIMATOLOGY BUT CONFIDENCE IN ANY
ONE SOLUTION NOT PARTICULARLY HIGH AT THIS POINT.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       MED   72%     HIGH  84%     HIGH  97%     MED   64%
KGSP       MED   78%     HIGH  96%     HIGH 100%     HIGH 100%
KAVL       HIGH  90%     HIGH  97%     HIGH  95%     MED   78%
KHKY       MED   67%     HIGH  82%     HIGH  90%     HIGH 100%
KGMU       MED   78%     HIGH  96%     HIGH 100%     HIGH 100%
KAND       MED   79%     HIGH 100%     HIGH  91%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED



000
FXUS62 KGSP 260750
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
350 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE OFF THE CAROLINA COAST THIS
MORNING...WITH A TRAILING COLD FRONT PUSHING THROUGH THE FORECAST
AREA. COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL CANADA
LATER TODAY AND WILL REMAIN THE DOMINANT FEATURE FOR THE BEGINNING
OF THE WORK WEEK. ANOTHER AREA OF LOW PRESSURE WILL MOVE EAST FROM
TEXAS TOWARD THE MIDDLE OF THE WEEK AND BRING MORE RAIN WEDNESDAY
AND THURSDAY...WITH A DRYING TREND FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM...SATELLITE AND RADAR IMAGES CONTINUES TO SHOW THE OLD
MCS ASHING OUT ACROSS THE WESTERN CAROLINAS. LATEST RUN OF THE CAMS
INDICATE THE COVERAGE WILL SPREAD EAST...GRADUALLY FADING TO CHC TO
SCHC. IS WAS INTERESTING TO SEE A SPLITTING CELL ACROSS CHESTERFIELD
CO AT 730Z. AT THE SFC...THE WEDGE FRONT RUNS FROM THE NORTHERN TIP
OF LAKE WATEREE...WEST ACROSS THE GSP METRO AREA...NORTH ALONG THE
EAST FACING SLOPES ACROSS THE NC FOOTHILLS. NORTH OF THE
BOUNDARY...LOW CLOUDS AND FOG WILL PERSIST THROUGH SUNRISE. LOW
CLOUDS AND FOG WILL DISSIPATE FROM THE SOUTH TO NORTH DURING THE
EARLY DAYLIGHT HOURS. BY MID DAY...THE CENTER OF LOW PRESSURE IS
EXPECTED TO PASS ACROSS THE UPSTATE OF SC...TRACKING EAST. A WEAK
BACKDOOR COLD FRONT WILL SWEEP SOUTH ACROSS THE REGION DURING THE
AFTERNOON. AS THE LOW PASSES...THE ENVIRONMENT BETWEEN I-85 TO I-77
COULD SUPPORT SCT TSRA DURING THE MID TO LATE AFTERNOON...I WILL
FORECAST CHC POPS. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM
AROUND 80 ACROSS THE UPPER SAVANNAH RIVER VALLEY TO THE MID 60S
ACROSS I-40 TO THE MTNS.

TONIGHT...IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL BUILD
ACROSS THE SOUTHERN APPALACHIAN REGION. CONDITIONS ACROSS THE REGION
SHOULD BECOME CLEAR TO MOSTLY CLEAR...WINDS BELOW 5 KTS...WITH
DEWPOINT DEPRESSION GREATER THAN 5 DEGREES. LOW TEMPERATURES SHOULD
FALL CLOSE TO NORMAL...FROM THE LOW 40S WITHIN THE MTN VALLEYS TO
LOW 50S ACROSS THE UPPER SAVANNAH RIVER VALLEY.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...SHORT TERM BEGINS WITH LARGE UPPER CLOSED LOW
SPINNING OVER NEW ENGLAND AND SOUTHEAST CANADA...WITH A REINFORCING
SHORTWAVE PUSHING AROUND THE WESTERN PERIPHERY OF THE TROUGH AT THE
BEGINNING OF THE PERIOD. SURFACE HIGH PRESSURE CENTERED OVER SOUTH
CENTRAL CANADA WILL BE RIDGING INTO THE SOUTHEAST. EXPECT A CLEARING
TREND DURING THE DAY ON MONDAY IN THE WAKE OF THE DRY UPPER TROUGH
AXIS PUSHING THROUGH WITH HIGHS BELOW NORMAL UNDER WEAK DEEP LAYER
CAA. CONTINUED BELOW-NORMAL TEMPERATURES MONDAY NIGHT AND WILL HAVE
TO KEEP AN EYE ON LOWS AT THE HIGHER ELEVATIONS IN CASE FROST MIGHT
BE A CONCERN...ESPECIALLY AS WINDS DIE OFF TOWARD SUNRISE TUESDAY.
THE COOL TEMPERATURES CONTINUE ON TUESDAY EVEN WITH MIDLEVEL RIDGING
BEGINNING TO BUILD IN ACROSS THE AREA.

A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL INDUCE CYCLOGENESIS
ACROSS THE NORTHERN GULF MONDAY NIGHT AND EARLY TUESDAY...SPREADING
MOISTURE INTO THE SOUTHEAST TUESDAY AFTERNOON AND EVENING. HAVE
CONTINUED TREND OF RAMPING UP POPS LATE IN THE DAY ON TUESDAY AS
ISENTROPIC UPGLIDE INCREASES ACROSS THE AREA. ECMWF IS BEGINNING TO
TREND A LITTLE FARTHER NORTH WITH THE SURFACE LOW...MORE INTO
SOUTHERN AND EVEN CENTRAL GEORGIA RATHER THAN REMAINING ALONG THE
FLORIDA PANHANDLE...WHICH MIGHT MEAN AN INCREASE IN QPF. OVERALL
MASS FIELDS NOT TOO DISSIMILAR BUT ENOUGH DIFFERENCES IN THE
DETAILS...ESPECIALLY TIMING AND PLACEMENT OF QPF...TO CONTINUE
BLANKETING THE AREA WITH HIGH CHANCE TO LOW LIKELY POPS AT BEST AS
WE TRANSITION INTO THE EXTENDED.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...CHANCE TO LIKELY POPS /ESPECIALLY FOR SOUTHERN
ZONES/ BEGIN THE PERIOD AS THE AFOREMENTIONED SURFACE LOW WORKS ITS
WAY EAST ACROSS SOUTHERN GEORGIA. WITH WIDESPREAD CLOUDINESS AND
RAIN...NOT TO MENTION DECREASING THICKNESSES PLUS JUST BEING ON THE
COLD SIDE OF THE SURFACE LOW...WE CONTINUE TO ADVERTISE HIGHS ON
WEDNESDAY WELL BELOW SEASONAL NORMALS...IN SOME LOCATIONS 10 DEGREES
OR SO.

MODEL INCONSISTENCIES AND RUN-TO-RUN DISCONTINUITY CONTINUE WITH
THIS SYSTEM AS THE 00Z GUIDANCE HAS ONCE AGAIN SWITCHED...WITH THE
GFS EXITING THE PRECIP FROM THE AREA FASTER THAN THE ECMWF.
CONTINUED THE COMPROMISE TREND...PULLING BACK ON POPS DURING THE DAY
ON THURSDAY. ECMWF WANTS TO BRING ANOTHER SHORTWAVE AROUND THE BASE
OF THE ELONGATED TROUGH THURSDAY NIGHT INTO FRIDAY BUT HAVE NOT
REFLECTED THIS IN THE GRIDS AT THIS TIME...PREFERRING INSTEAD THE
DRIER SOLUTIONS...HOWEVER AS WE MOVE FORWARD THIS MAY NEED TO BE
REEVALUATED. WE SHOULD SEE A DRYING TREND INTO THE WEEKEND WITH
TEMPERATURES TRENDING MORE TOWARDS CLIMATOLOGY BUT CONFIDENCE IN ANY
ONE SOLUTION NOT PARTICULARLY HIGH AT THIS POINT.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       MED   72%     HIGH  84%     HIGH  97%     MED   64%
KGSP       MED   78%     HIGH  96%     HIGH 100%     HIGH 100%
KAVL       HIGH  90%     HIGH  97%     HIGH  95%     MED   78%
KHKY       MED   67%     HIGH  82%     HIGH  90%     HIGH 100%
KGMU       MED   78%     HIGH  96%     HIGH 100%     HIGH 100%
KAND       MED   79%     HIGH 100%     HIGH  91%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED



000
FXUS62 KGSP 260750
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
350 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE OFF THE CAROLINA COAST THIS
MORNING...WITH A TRAILING COLD FRONT PUSHING THROUGH THE FORECAST
AREA. COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL CANADA
LATER TODAY AND WILL REMAIN THE DOMINANT FEATURE FOR THE BEGINNING
OF THE WORK WEEK. ANOTHER AREA OF LOW PRESSURE WILL MOVE EAST FROM
TEXAS TOWARD THE MIDDLE OF THE WEEK AND BRING MORE RAIN WEDNESDAY
AND THURSDAY...WITH A DRYING TREND FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM...SATELLITE AND RADAR IMAGES CONTINUES TO SHOW THE OLD
MCS ASHING OUT ACROSS THE WESTERN CAROLINAS. LATEST RUN OF THE CAMS
INDICATE THE COVERAGE WILL SPREAD EAST...GRADUALLY FADING TO CHC TO
SCHC. IS WAS INTERESTING TO SEE A SPLITTING CELL ACROSS CHESTERFIELD
CO AT 730Z. AT THE SFC...THE WEDGE FRONT RUNS FROM THE NORTHERN TIP
OF LAKE WATEREE...WEST ACROSS THE GSP METRO AREA...NORTH ALONG THE
EAST FACING SLOPES ACROSS THE NC FOOTHILLS. NORTH OF THE
BOUNDARY...LOW CLOUDS AND FOG WILL PERSIST THROUGH SUNRISE. LOW
CLOUDS AND FOG WILL DISSIPATE FROM THE SOUTH TO NORTH DURING THE
EARLY DAYLIGHT HOURS. BY MID DAY...THE CENTER OF LOW PRESSURE IS
EXPECTED TO PASS ACROSS THE UPSTATE OF SC...TRACKING EAST. A WEAK
BACKDOOR COLD FRONT WILL SWEEP SOUTH ACROSS THE REGION DURING THE
AFTERNOON. AS THE LOW PASSES...THE ENVIRONMENT BETWEEN I-85 TO I-77
COULD SUPPORT SCT TSRA DURING THE MID TO LATE AFTERNOON...I WILL
FORECAST CHC POPS. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM
AROUND 80 ACROSS THE UPPER SAVANNAH RIVER VALLEY TO THE MID 60S
ACROSS I-40 TO THE MTNS.

TONIGHT...IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL BUILD
ACROSS THE SOUTHERN APPALACHIAN REGION. CONDITIONS ACROSS THE REGION
SHOULD BECOME CLEAR TO MOSTLY CLEAR...WINDS BELOW 5 KTS...WITH
DEWPOINT DEPRESSION GREATER THAN 5 DEGREES. LOW TEMPERATURES SHOULD
FALL CLOSE TO NORMAL...FROM THE LOW 40S WITHIN THE MTN VALLEYS TO
LOW 50S ACROSS THE UPPER SAVANNAH RIVER VALLEY.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...SHORT TERM BEGINS WITH LARGE UPPER CLOSED LOW
SPINNING OVER NEW ENGLAND AND SOUTHEAST CANADA...WITH A REINFORCING
SHORTWAVE PUSHING AROUND THE WESTERN PERIPHERY OF THE TROUGH AT THE
BEGINNING OF THE PERIOD. SURFACE HIGH PRESSURE CENTERED OVER SOUTH
CENTRAL CANADA WILL BE RIDGING INTO THE SOUTHEAST. EXPECT A CLEARING
TREND DURING THE DAY ON MONDAY IN THE WAKE OF THE DRY UPPER TROUGH
AXIS PUSHING THROUGH WITH HIGHS BELOW NORMAL UNDER WEAK DEEP LAYER
CAA. CONTINUED BELOW-NORMAL TEMPERATURES MONDAY NIGHT AND WILL HAVE
TO KEEP AN EYE ON LOWS AT THE HIGHER ELEVATIONS IN CASE FROST MIGHT
BE A CONCERN...ESPECIALLY AS WINDS DIE OFF TOWARD SUNRISE TUESDAY.
THE COOL TEMPERATURES CONTINUE ON TUESDAY EVEN WITH MIDLEVEL RIDGING
BEGINNING TO BUILD IN ACROSS THE AREA.

A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL INDUCE CYCLOGENESIS
ACROSS THE NORTHERN GULF MONDAY NIGHT AND EARLY TUESDAY...SPREADING
MOISTURE INTO THE SOUTHEAST TUESDAY AFTERNOON AND EVENING. HAVE
CONTINUED TREND OF RAMPING UP POPS LATE IN THE DAY ON TUESDAY AS
ISENTROPIC UPGLIDE INCREASES ACROSS THE AREA. ECMWF IS BEGINNING TO
TREND A LITTLE FARTHER NORTH WITH THE SURFACE LOW...MORE INTO
SOUTHERN AND EVEN CENTRAL GEORGIA RATHER THAN REMAINING ALONG THE
FLORIDA PANHANDLE...WHICH MIGHT MEAN AN INCREASE IN QPF. OVERALL
MASS FIELDS NOT TOO DISSIMILAR BUT ENOUGH DIFFERENCES IN THE
DETAILS...ESPECIALLY TIMING AND PLACEMENT OF QPF...TO CONTINUE
BLANKETING THE AREA WITH HIGH CHANCE TO LOW LIKELY POPS AT BEST AS
WE TRANSITION INTO THE EXTENDED.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...CHANCE TO LIKELY POPS /ESPECIALLY FOR SOUTHERN
ZONES/ BEGIN THE PERIOD AS THE AFOREMENTIONED SURFACE LOW WORKS ITS
WAY EAST ACROSS SOUTHERN GEORGIA. WITH WIDESPREAD CLOUDINESS AND
RAIN...NOT TO MENTION DECREASING THICKNESSES PLUS JUST BEING ON THE
COLD SIDE OF THE SURFACE LOW...WE CONTINUE TO ADVERTISE HIGHS ON
WEDNESDAY WELL BELOW SEASONAL NORMALS...IN SOME LOCATIONS 10 DEGREES
OR SO.

MODEL INCONSISTENCIES AND RUN-TO-RUN DISCONTINUITY CONTINUE WITH
THIS SYSTEM AS THE 00Z GUIDANCE HAS ONCE AGAIN SWITCHED...WITH THE
GFS EXITING THE PRECIP FROM THE AREA FASTER THAN THE ECMWF.
CONTINUED THE COMPROMISE TREND...PULLING BACK ON POPS DURING THE DAY
ON THURSDAY. ECMWF WANTS TO BRING ANOTHER SHORTWAVE AROUND THE BASE
OF THE ELONGATED TROUGH THURSDAY NIGHT INTO FRIDAY BUT HAVE NOT
REFLECTED THIS IN THE GRIDS AT THIS TIME...PREFERRING INSTEAD THE
DRIER SOLUTIONS...HOWEVER AS WE MOVE FORWARD THIS MAY NEED TO BE
REEVALUATED. WE SHOULD SEE A DRYING TREND INTO THE WEEKEND WITH
TEMPERATURES TRENDING MORE TOWARDS CLIMATOLOGY BUT CONFIDENCE IN ANY
ONE SOLUTION NOT PARTICULARLY HIGH AT THIS POINT.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       MED   72%     HIGH  84%     HIGH  97%     MED   64%
KGSP       MED   78%     HIGH  96%     HIGH 100%     HIGH 100%
KAVL       HIGH  90%     HIGH  97%     HIGH  95%     MED   78%
KHKY       MED   67%     HIGH  82%     HIGH  90%     HIGH 100%
KGMU       MED   78%     HIGH  96%     HIGH 100%     HIGH 100%
KAND       MED   79%     HIGH 100%     HIGH  91%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED



000
FXUS62 KGSP 260750
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
350 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE OFF THE CAROLINA COAST THIS
MORNING...WITH A TRAILING COLD FRONT PUSHING THROUGH THE FORECAST
AREA. COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL CANADA
LATER TODAY AND WILL REMAIN THE DOMINANT FEATURE FOR THE BEGINNING
OF THE WORK WEEK. ANOTHER AREA OF LOW PRESSURE WILL MOVE EAST FROM
TEXAS TOWARD THE MIDDLE OF THE WEEK AND BRING MORE RAIN WEDNESDAY
AND THURSDAY...WITH A DRYING TREND FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM...SATELLITE AND RADAR IMAGES CONTINUES TO SHOW THE OLD
MCS ASHING OUT ACROSS THE WESTERN CAROLINAS. LATEST RUN OF THE CAMS
INDICATE THE COVERAGE WILL SPREAD EAST...GRADUALLY FADING TO CHC TO
SCHC. IS WAS INTERESTING TO SEE A SPLITTING CELL ACROSS CHESTERFIELD
CO AT 730Z. AT THE SFC...THE WEDGE FRONT RUNS FROM THE NORTHERN TIP
OF LAKE WATEREE...WEST ACROSS THE GSP METRO AREA...NORTH ALONG THE
EAST FACING SLOPES ACROSS THE NC FOOTHILLS. NORTH OF THE
BOUNDARY...LOW CLOUDS AND FOG WILL PERSIST THROUGH SUNRISE. LOW
CLOUDS AND FOG WILL DISSIPATE FROM THE SOUTH TO NORTH DURING THE
EARLY DAYLIGHT HOURS. BY MID DAY...THE CENTER OF LOW PRESSURE IS
EXPECTED TO PASS ACROSS THE UPSTATE OF SC...TRACKING EAST. A WEAK
BACKDOOR COLD FRONT WILL SWEEP SOUTH ACROSS THE REGION DURING THE
AFTERNOON. AS THE LOW PASSES...THE ENVIRONMENT BETWEEN I-85 TO I-77
COULD SUPPORT SCT TSRA DURING THE MID TO LATE AFTERNOON...I WILL
FORECAST CHC POPS. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM
AROUND 80 ACROSS THE UPPER SAVANNAH RIVER VALLEY TO THE MID 60S
ACROSS I-40 TO THE MTNS.

TONIGHT...IN THE WAKE OF THE COLD FRONT...HIGH PRESSURE WILL BUILD
ACROSS THE SOUTHERN APPALACHIAN REGION. CONDITIONS ACROSS THE REGION
SHOULD BECOME CLEAR TO MOSTLY CLEAR...WINDS BELOW 5 KTS...WITH
DEWPOINT DEPRESSION GREATER THAN 5 DEGREES. LOW TEMPERATURES SHOULD
FALL CLOSE TO NORMAL...FROM THE LOW 40S WITHIN THE MTN VALLEYS TO
LOW 50S ACROSS THE UPPER SAVANNAH RIVER VALLEY.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM SUNDAY...SHORT TERM BEGINS WITH LARGE UPPER CLOSED LOW
SPINNING OVER NEW ENGLAND AND SOUTHEAST CANADA...WITH A REINFORCING
SHORTWAVE PUSHING AROUND THE WESTERN PERIPHERY OF THE TROUGH AT THE
BEGINNING OF THE PERIOD. SURFACE HIGH PRESSURE CENTERED OVER SOUTH
CENTRAL CANADA WILL BE RIDGING INTO THE SOUTHEAST. EXPECT A CLEARING
TREND DURING THE DAY ON MONDAY IN THE WAKE OF THE DRY UPPER TROUGH
AXIS PUSHING THROUGH WITH HIGHS BELOW NORMAL UNDER WEAK DEEP LAYER
CAA. CONTINUED BELOW-NORMAL TEMPERATURES MONDAY NIGHT AND WILL HAVE
TO KEEP AN EYE ON LOWS AT THE HIGHER ELEVATIONS IN CASE FROST MIGHT
BE A CONCERN...ESPECIALLY AS WINDS DIE OFF TOWARD SUNRISE TUESDAY.
THE COOL TEMPERATURES CONTINUE ON TUESDAY EVEN WITH MIDLEVEL RIDGING
BEGINNING TO BUILD IN ACROSS THE AREA.

A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL INDUCE CYCLOGENESIS
ACROSS THE NORTHERN GULF MONDAY NIGHT AND EARLY TUESDAY...SPREADING
MOISTURE INTO THE SOUTHEAST TUESDAY AFTERNOON AND EVENING. HAVE
CONTINUED TREND OF RAMPING UP POPS LATE IN THE DAY ON TUESDAY AS
ISENTROPIC UPGLIDE INCREASES ACROSS THE AREA. ECMWF IS BEGINNING TO
TREND A LITTLE FARTHER NORTH WITH THE SURFACE LOW...MORE INTO
SOUTHERN AND EVEN CENTRAL GEORGIA RATHER THAN REMAINING ALONG THE
FLORIDA PANHANDLE...WHICH MIGHT MEAN AN INCREASE IN QPF. OVERALL
MASS FIELDS NOT TOO DISSIMILAR BUT ENOUGH DIFFERENCES IN THE
DETAILS...ESPECIALLY TIMING AND PLACEMENT OF QPF...TO CONTINUE
BLANKETING THE AREA WITH HIGH CHANCE TO LOW LIKELY POPS AT BEST AS
WE TRANSITION INTO THE EXTENDED.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...CHANCE TO LIKELY POPS /ESPECIALLY FOR SOUTHERN
ZONES/ BEGIN THE PERIOD AS THE AFOREMENTIONED SURFACE LOW WORKS ITS
WAY EAST ACROSS SOUTHERN GEORGIA. WITH WIDESPREAD CLOUDINESS AND
RAIN...NOT TO MENTION DECREASING THICKNESSES PLUS JUST BEING ON THE
COLD SIDE OF THE SURFACE LOW...WE CONTINUE TO ADVERTISE HIGHS ON
WEDNESDAY WELL BELOW SEASONAL NORMALS...IN SOME LOCATIONS 10 DEGREES
OR SO.

MODEL INCONSISTENCIES AND RUN-TO-RUN DISCONTINUITY CONTINUE WITH
THIS SYSTEM AS THE 00Z GUIDANCE HAS ONCE AGAIN SWITCHED...WITH THE
GFS EXITING THE PRECIP FROM THE AREA FASTER THAN THE ECMWF.
CONTINUED THE COMPROMISE TREND...PULLING BACK ON POPS DURING THE DAY
ON THURSDAY. ECMWF WANTS TO BRING ANOTHER SHORTWAVE AROUND THE BASE
OF THE ELONGATED TROUGH THURSDAY NIGHT INTO FRIDAY BUT HAVE NOT
REFLECTED THIS IN THE GRIDS AT THIS TIME...PREFERRING INSTEAD THE
DRIER SOLUTIONS...HOWEVER AS WE MOVE FORWARD THIS MAY NEED TO BE
REEVALUATED. WE SHOULD SEE A DRYING TREND INTO THE WEEKEND WITH
TEMPERATURES TRENDING MORE TOWARDS CLIMATOLOGY BUT CONFIDENCE IN ANY
ONE SOLUTION NOT PARTICULARLY HIGH AT THIS POINT.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       MED   72%     HIGH  84%     HIGH  97%     MED   64%
KGSP       MED   78%     HIGH  96%     HIGH 100%     HIGH 100%
KAVL       HIGH  90%     HIGH  97%     HIGH  95%     MED   78%
KHKY       MED   67%     HIGH  82%     HIGH  90%     HIGH 100%
KGMU       MED   78%     HIGH  96%     HIGH 100%     HIGH 100%
KAND       MED   79%     HIGH 100%     HIGH  91%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED




000
FXUS62 KGSP 260602
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
202 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 150 AM...AS ANTICIPATE THE MCS IS FADING ACROSS THE SOUTHERN
APPALACHIAN MOUNTAINS. HOWEVER...CELL MOVEMENT RANGES FROM 30-40 KTS
AND STRUCTURE REMAINS INTACT ACROSS THE CENTRAL PORTION OF THE
CONVECTIVE LINE...UPSTREAM OF THE NC FOOTHILLS. THE ENVIRONMENT EAST
ACROSS THE NC FOOTHILLS AND PIEDMONT IS AND WILL REMAIN STABLE FOR
SURFACE BASED PARCELS. HOWEVER...ELEVATED CAPE MAY REMAIN AROUND 500
J/KG EAST OF THE MTNS. I WILL EXPECTED THAT THE LINE WILL CONTINUE
TO WEAKEN...BUT MAY TRACK ACROSS THE NRN HALF OF THE CWA EARLY THIS
MORNING. I WILL UPDATE THE FORECAST TO ADJUST POPS...MAKE SIGNIFICANT
CHANGES TO SKY...AND TWEAK TEMPS.

AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       MED   70%     HIGH  88%     HIGH  96%     MED   65%
KGSP       MED   76%     HIGH  97%     HIGH 100%     HIGH 100%
KAVL       HIGH  87%     HIGH  96%     HIGH  96%     MED   78%
KHKY       MED   70%     MED   78%     HIGH  89%     HIGH 100%
KGMU       MED   69%     HIGH  94%     HIGH 100%     HIGH 100%
KAND       HIGH  83%     HIGH 100%     HIGH  92%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...NED




000
FXUS62 KGSP 260602
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
202 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 150 AM...AS ANTICIPATE THE MCS IS FADING ACROSS THE SOUTHERN
APPALACHIAN MOUNTAINS. HOWEVER...CELL MOVEMENT RANGES FROM 30-40 KTS
AND STRUCTURE REMAINS INTACT ACROSS THE CENTRAL PORTION OF THE
CONVECTIVE LINE...UPSTREAM OF THE NC FOOTHILLS. THE ENVIRONMENT EAST
ACROSS THE NC FOOTHILLS AND PIEDMONT IS AND WILL REMAIN STABLE FOR
SURFACE BASED PARCELS. HOWEVER...ELEVATED CAPE MAY REMAIN AROUND 500
J/KG EAST OF THE MTNS. I WILL EXPECTED THAT THE LINE WILL CONTINUE
TO WEAKEN...BUT MAY TRACK ACROSS THE NRN HALF OF THE CWA EARLY THIS
MORNING. I WILL UPDATE THE FORECAST TO ADJUST POPS...MAKE SIGNIFICANT
CHANGES TO SKY...AND TWEAK TEMPS.

AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       MED   70%     HIGH  88%     HIGH  96%     MED   65%
KGSP       MED   76%     HIGH  97%     HIGH 100%     HIGH 100%
KAVL       HIGH  87%     HIGH  96%     HIGH  96%     MED   78%
KHKY       MED   70%     MED   78%     HIGH  89%     HIGH 100%
KGMU       MED   69%     HIGH  94%     HIGH 100%     HIGH 100%
KAND       HIGH  83%     HIGH 100%     HIGH  92%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...NED




000
FXUS62 KGSP 260602
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
202 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 150 AM...AS ANTICIPATE THE MCS IS FADING ACROSS THE SOUTHERN
APPALACHIAN MOUNTAINS. HOWEVER...CELL MOVEMENT RANGES FROM 30-40 KTS
AND STRUCTURE REMAINS INTACT ACROSS THE CENTRAL PORTION OF THE
CONVECTIVE LINE...UPSTREAM OF THE NC FOOTHILLS. THE ENVIRONMENT EAST
ACROSS THE NC FOOTHILLS AND PIEDMONT IS AND WILL REMAIN STABLE FOR
SURFACE BASED PARCELS. HOWEVER...ELEVATED CAPE MAY REMAIN AROUND 500
J/KG EAST OF THE MTNS. I WILL EXPECTED THAT THE LINE WILL CONTINUE
TO WEAKEN...BUT MAY TRACK ACROSS THE NRN HALF OF THE CWA EARLY THIS
MORNING. I WILL UPDATE THE FORECAST TO ADJUST POPS...MAKE SIGNIFICANT
CHANGES TO SKY...AND TWEAK TEMPS.

AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       MED   70%     HIGH  88%     HIGH  96%     MED   65%
KGSP       MED   76%     HIGH  97%     HIGH 100%     HIGH 100%
KAVL       HIGH  87%     HIGH  96%     HIGH  96%     MED   78%
KHKY       MED   70%     MED   78%     HIGH  89%     HIGH 100%
KGMU       MED   69%     HIGH  94%     HIGH 100%     HIGH 100%
KAND       HIGH  83%     HIGH 100%     HIGH  92%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...NED




000
FXUS62 KGSP 260602
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
202 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 150 AM...AS ANTICIPATE THE MCS IS FADING ACROSS THE SOUTHERN
APPALACHIAN MOUNTAINS. HOWEVER...CELL MOVEMENT RANGES FROM 30-40 KTS
AND STRUCTURE REMAINS INTACT ACROSS THE CENTRAL PORTION OF THE
CONVECTIVE LINE...UPSTREAM OF THE NC FOOTHILLS. THE ENVIRONMENT EAST
ACROSS THE NC FOOTHILLS AND PIEDMONT IS AND WILL REMAIN STABLE FOR
SURFACE BASED PARCELS. HOWEVER...ELEVATED CAPE MAY REMAIN AROUND 500
J/KG EAST OF THE MTNS. I WILL EXPECTED THAT THE LINE WILL CONTINUE
TO WEAKEN...BUT MAY TRACK ACROSS THE NRN HALF OF THE CWA EARLY THIS
MORNING. I WILL UPDATE THE FORECAST TO ADJUST POPS...MAKE SIGNIFICANT
CHANGES TO SKY...AND TWEAK TEMPS.

AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       MED   70%     HIGH  88%     HIGH  96%     MED   65%
KGSP       MED   76%     HIGH  97%     HIGH 100%     HIGH 100%
KAVL       HIGH  87%     HIGH  96%     HIGH  96%     MED   78%
KHKY       MED   70%     MED   78%     HIGH  89%     HIGH 100%
KGMU       MED   69%     HIGH  94%     HIGH 100%     HIGH 100%
KAND       HIGH  83%     HIGH 100%     HIGH  92%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...NED




000
FXUS62 KGSP 260602
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
202 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 150 AM...AS ANTICIPATE THE MCS IS FADING ACROSS THE SOUTHERN
APPALACHIAN MOUNTAINS. HOWEVER...CELL MOVEMENT RANGES FROM 30-40 KTS
AND STRUCTURE REMAINS INTACT ACROSS THE CENTRAL PORTION OF THE
CONVECTIVE LINE...UPSTREAM OF THE NC FOOTHILLS. THE ENVIRONMENT EAST
ACROSS THE NC FOOTHILLS AND PIEDMONT IS AND WILL REMAIN STABLE FOR
SURFACE BASED PARCELS. HOWEVER...ELEVATED CAPE MAY REMAIN AROUND 500
J/KG EAST OF THE MTNS. I WILL EXPECTED THAT THE LINE WILL CONTINUE
TO WEAKEN...BUT MAY TRACK ACROSS THE NRN HALF OF THE CWA EARLY THIS
MORNING. I WILL UPDATE THE FORECAST TO ADJUST POPS...MAKE SIGNIFICANT
CHANGES TO SKY...AND TWEAK TEMPS.

AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       MED   70%     HIGH  88%     HIGH  96%     MED   65%
KGSP       MED   76%     HIGH  97%     HIGH 100%     HIGH 100%
KAVL       HIGH  87%     HIGH  96%     HIGH  96%     MED   78%
KHKY       MED   70%     MED   78%     HIGH  89%     HIGH 100%
KGMU       MED   69%     HIGH  94%     HIGH 100%     HIGH 100%
KAND       HIGH  83%     HIGH 100%     HIGH  92%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...NED




000
FXUS62 KGSP 260602
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
202 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 150 AM...AS ANTICIPATE THE MCS IS FADING ACROSS THE SOUTHERN
APPALACHIAN MOUNTAINS. HOWEVER...CELL MOVEMENT RANGES FROM 30-40 KTS
AND STRUCTURE REMAINS INTACT ACROSS THE CENTRAL PORTION OF THE
CONVECTIVE LINE...UPSTREAM OF THE NC FOOTHILLS. THE ENVIRONMENT EAST
ACROSS THE NC FOOTHILLS AND PIEDMONT IS AND WILL REMAIN STABLE FOR
SURFACE BASED PARCELS. HOWEVER...ELEVATED CAPE MAY REMAIN AROUND 500
J/KG EAST OF THE MTNS. I WILL EXPECTED THAT THE LINE WILL CONTINUE
TO WEAKEN...BUT MAY TRACK ACROSS THE NRN HALF OF THE CWA EARLY THIS
MORNING. I WILL UPDATE THE FORECAST TO ADJUST POPS...MAKE SIGNIFICANT
CHANGES TO SKY...AND TWEAK TEMPS.

AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       MED   70%     HIGH  88%     HIGH  96%     MED   65%
KGSP       MED   76%     HIGH  97%     HIGH 100%     HIGH 100%
KAVL       HIGH  87%     HIGH  96%     HIGH  96%     MED   78%
KHKY       MED   70%     MED   78%     HIGH  89%     HIGH 100%
KGMU       MED   69%     HIGH  94%     HIGH 100%     HIGH 100%
KAND       HIGH  83%     HIGH 100%     HIGH  92%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...NED




000
FXUS62 KGSP 260602
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
202 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 150 AM...AS ANTICIPATE THE MCS IS FADING ACROSS THE SOUTHERN
APPALACHIAN MOUNTAINS. HOWEVER...CELL MOVEMENT RANGES FROM 30-40 KTS
AND STRUCTURE REMAINS INTACT ACROSS THE CENTRAL PORTION OF THE
CONVECTIVE LINE...UPSTREAM OF THE NC FOOTHILLS. THE ENVIRONMENT EAST
ACROSS THE NC FOOTHILLS AND PIEDMONT IS AND WILL REMAIN STABLE FOR
SURFACE BASED PARCELS. HOWEVER...ELEVATED CAPE MAY REMAIN AROUND 500
J/KG EAST OF THE MTNS. I WILL EXPECTED THAT THE LINE WILL CONTINUE
TO WEAKEN...BUT MAY TRACK ACROSS THE NRN HALF OF THE CWA EARLY THIS
MORNING. I WILL UPDATE THE FORECAST TO ADJUST POPS...MAKE SIGNIFICANT
CHANGES TO SKY...AND TWEAK TEMPS.

AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       MED   70%     HIGH  88%     HIGH  96%     MED   65%
KGSP       MED   76%     HIGH  97%     HIGH 100%     HIGH 100%
KAVL       HIGH  87%     HIGH  96%     HIGH  96%     MED   78%
KHKY       MED   70%     MED   78%     HIGH  89%     HIGH 100%
KGMU       MED   69%     HIGH  94%     HIGH 100%     HIGH 100%
KAND       HIGH  83%     HIGH 100%     HIGH  92%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...NED




000
FXUS62 KGSP 260602
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
202 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 150 AM...AS ANTICIPATE THE MCS IS FADING ACROSS THE SOUTHERN
APPALACHIAN MOUNTAINS. HOWEVER...CELL MOVEMENT RANGES FROM 30-40 KTS
AND STRUCTURE REMAINS INTACT ACROSS THE CENTRAL PORTION OF THE
CONVECTIVE LINE...UPSTREAM OF THE NC FOOTHILLS. THE ENVIRONMENT EAST
ACROSS THE NC FOOTHILLS AND PIEDMONT IS AND WILL REMAIN STABLE FOR
SURFACE BASED PARCELS. HOWEVER...ELEVATED CAPE MAY REMAIN AROUND 500
J/KG EAST OF THE MTNS. I WILL EXPECTED THAT THE LINE WILL CONTINUE
TO WEAKEN...BUT MAY TRACK ACROSS THE NRN HALF OF THE CWA EARLY THIS
MORNING. I WILL UPDATE THE FORECAST TO ADJUST POPS...MAKE SIGNIFICANT
CHANGES TO SKY...AND TWEAK TEMPS.

AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       MED   70%     HIGH  88%     HIGH  96%     MED   65%
KGSP       MED   76%     HIGH  97%     HIGH 100%     HIGH 100%
KAVL       HIGH  87%     HIGH  96%     HIGH  96%     MED   78%
KHKY       MED   70%     MED   78%     HIGH  89%     HIGH 100%
KGMU       MED   69%     HIGH  94%     HIGH 100%     HIGH 100%
KAND       HIGH  83%     HIGH 100%     HIGH  92%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...NED




000
FXUS62 KGSP 260602
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
202 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 150 AM...AS ANTICIPATE THE MCS IS FADING ACROSS THE SOUTHERN
APPALACHIAN MOUNTAINS. HOWEVER...CELL MOVEMENT RANGES FROM 30-40 KTS
AND STRUCTURE REMAINS INTACT ACROSS THE CENTRAL PORTION OF THE
CONVECTIVE LINE...UPSTREAM OF THE NC FOOTHILLS. THE ENVIRONMENT EAST
ACROSS THE NC FOOTHILLS AND PIEDMONT IS AND WILL REMAIN STABLE FOR
SURFACE BASED PARCELS. HOWEVER...ELEVATED CAPE MAY REMAIN AROUND 500
J/KG EAST OF THE MTNS. I WILL EXPECTED THAT THE LINE WILL CONTINUE
TO WEAKEN...BUT MAY TRACK ACROSS THE NRN HALF OF THE CWA EARLY THIS
MORNING. I WILL UPDATE THE FORECAST TO ADJUST POPS...MAKE SIGNIFICANT
CHANGES TO SKY...AND TWEAK TEMPS.

AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       MED   70%     HIGH  88%     HIGH  96%     MED   65%
KGSP       MED   76%     HIGH  97%     HIGH 100%     HIGH 100%
KAVL       HIGH  87%     HIGH  96%     HIGH  96%     MED   78%
KHKY       MED   70%     MED   78%     HIGH  89%     HIGH 100%
KGMU       MED   69%     HIGH  94%     HIGH 100%     HIGH 100%
KAND       HIGH  83%     HIGH 100%     HIGH  92%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...NED




000
FXUS62 KGSP 260602
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
202 AM EDT SUN APR 26 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 150 AM...AS ANTICIPATE THE MCS IS FADING ACROSS THE SOUTHERN
APPALACHIAN MOUNTAINS. HOWEVER...CELL MOVEMENT RANGES FROM 30-40 KTS
AND STRUCTURE REMAINS INTACT ACROSS THE CENTRAL PORTION OF THE
CONVECTIVE LINE...UPSTREAM OF THE NC FOOTHILLS. THE ENVIRONMENT EAST
ACROSS THE NC FOOTHILLS AND PIEDMONT IS AND WILL REMAIN STABLE FOR
SURFACE BASED PARCELS. HOWEVER...ELEVATED CAPE MAY REMAIN AROUND 500
J/KG EAST OF THE MTNS. I WILL EXPECTED THAT THE LINE WILL CONTINUE
TO WEAKEN...BUT MAY TRACK ACROSS THE NRN HALF OF THE CWA EARLY THIS
MORNING. I WILL UPDATE THE FORECAST TO ADJUST POPS...MAKE SIGNIFICANT
CHANGES TO SKY...AND TWEAK TEMPS.

AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...LATEST SFC ANALYSIS AND SATELLITE IMAGES
INDICATED THAT THE WEDGE BOUNDARY WAS CURVED FROM THE NORTHERN TIP
OF LAKE WATEREE...ACROSS THE GSP METRO...THEN NORTH ALONG THE EAST
FACING SLOPES ACROSS THE NC FOOTHILLS. AREAS NORTH OF THE BOUNDARY
WERE OBSERVING LIFR CEILINGS WITH POCKETS OF LIFR VIS. HOWEVER...A
WEAKENING MCS WILL LIKELY TRACK ACROSS THE MTNS...GENERALLY EAST BY
8Z. THE PASSAGE OF THE DECAYING CONVECTION MAY MIX OUT THE LLVL
CEILINGS AND VIS...BUT EXPECT THE RESTRICTIONS TO REDEVELOP.
KCLT...KHKY...KGSP...AND KGMU ARE EXPECTED TO REMAIN WITHIN THE
CORRIDOR OF LOW CEILINGS AND VIS THROUGH SUNRISE...THEN CONDITIONS
SHOULD IMPROVE TO MVFR BY MID MORNING...THEN VFR BY MID DAY. KAVL
AND KAND WILL REMAIN REMOVED FROM THE WEDGED AIR MASS...COMBINED
WITH WINDS ABOVE 5 KTS...CONDITIONS ARE GENERALLY EXPECTED TO REMAIN
MVFR OR HIGHER THIS MORNING. THE REST OF THE DAY SHOULD FEATURE BKN
LOW TO MID CLOUDS...THICKER AND MORE PERSISTENT ACROSS KHKY AND
KCLT. FURTHER SOUTH...KAND SHOULD SEE GUSTY WEST WINDS THROUGH THE
DAYLIGHT HOURS. ALL TERMINALS SHOULD SEE WINDS TURN FROM THE NORTH
LATE THIS AFTERNOON AND EARLY EVENING FOLLOWING A COLD FRONT.


OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON
SUNDAY THEN  FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER
LOW PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       MED   70%     HIGH  88%     HIGH  96%     MED   65%
KGSP       MED   76%     HIGH  97%     HIGH 100%     HIGH 100%
KAVL       HIGH  87%     HIGH  96%     HIGH  96%     MED   78%
KHKY       MED   70%     MED   78%     HIGH  89%     HIGH 100%
KGMU       MED   69%     HIGH  94%     HIGH 100%     HIGH 100%
KAND       HIGH  83%     HIGH 100%     HIGH  92%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...NED



000
FXUS62 KCAE 260553
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
153 AM EDT SUN APR 26 2015

.SYNOPSIS...
DRIER WEATHER RETURNS FOR SUNDAY AS A COLD FRONT MOVES SOUTH ACROSS
THE REGION. THE NEXT CHANCE FOR SIGNIFICANT RAIN MOVES IN FOR THE
MIDDLE OF NEXT WEEK AS MOISTURE INCREASES AHEAD OF A LOW PRESSURE
SYSTEM COMING OUT OF THE GULF OF MEXICO.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A FRONTAL BOUNDARY IS POSITIONED JUST SOUTH OF THE NC/SC BORDER
TONIGHT. OBSERVATIONS SHOW NORTHEASTERLY WINDS NORTH OF THE
BOUNDARY AND SOUTHWESTERLY WINDS FOR A MAJORITY OF THE FORECAST
AREA WHICH IS SOUTH OF THE BOUNDARY. EXPECT ISOLATED SHOWERS AND
STORMS TO CONTINUE BEHIND THE QLCS DEPARTING OFF THE COAST. THE
HIGHEST MOISTURE IS CURRENTLY ALONG THE SOUTHERN AND EASTERN
COUNTIES. MESOANALYSIS ALSO SHOWS WEAK TO MODERATE INSTABILITY
REMAINS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WITH LIFTED
INDICES AS LOW AS -4/-5 IN THE SOUTHERNMOST PART OF THE FA. EXPECT
THIS AREA TO SEE A MAJORITY OF THE SHOWER ACTIVITY OVER THE NEXT
HOUR OR TWO. THE HRRR SEEMS TO BE HANDLING THE ACTIVITY FAIRLY
WELL AND SHOWS MOST OF THE ACTIVITY DEPARTING THE FORECAST AREA BY
06Z SO HAVE TRENDED POPS DOWN OVERNIGHT. OBSERVATIONS SHOW LOW
VISIBILITIES IN LANCASTER AND CHESTERFIELD COUNTIES CLOSE TO THE
FRONTAL BOUNDARY ALTHOUGH LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL
SOME OVERNIGHT. OVERNIGHT LOWS REMAIN MILD...ONLY FALLING INTO THE
LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
EVENING CONVECTION HAS SHIFTED EAST OF THE AREA AND DRIER AIR
ALOFT IS MOVING IN. SURFACE LOW PRESSURE IS MOVING EASTWARD ACROSS
THE NC/VA MOUNTAINS AND WILL CONTINUE TO SHIFT EAST ACROSS NC
THROUGH THE DAY. CURRENT SATELLITE IMAGERY SHOWS WIDESPREAD LIFR
STRATUS/FOG ON THE NORTHSIDE OF A NEARLY STATIONARY FRONT ACROSS
THE NORTHERN MIDLANDS. THIS FRONT AND RESTRICTIONS ARE EXPECTED TO
REMAIN NORTH OF THE TERMINALS OVERNIGHT BUT THERE HAVE BEEN SIGNS
OF POCKETS OF LOW CLOUDS DEVELOPING DUE TO NOCTURNAL COOLING AND
MOS GUIDANCE IS SUGGESTING A PERIOD OF MVFR/IFR CIGS IMPACTING THE
TERMINALS. CONFIDENCE IS LOW IN THE IFR CIGS DEVELOPING BUT WILL
CARRY A PERIOD OF MVFR CIGS 08Z-12Z. STRONG LOW LEVEL JET AROUND
35 KNOTS SHOULD PREVENT/LIMIT FOG DEVELOPMENT ALTHOUGH IT CANNOT
BE RULED OUT.

INCREASING PRESSURE GRADIENT AND STRONG LOW LEVEL WIND FIELD WILL
ALLOW STRONG MIXING TO OCCUR DURING THE DAY TODAY AND EXPECT
BREEZY WESTERLY WINDS AROUND 15 KNOTS WITH GUSTS AROUND 25 KNOTS.
STRONG INSTABILITY THIS AFTERNOON BUT LIMITED MOISTURE PRECLUDES
ANY MENTION OF TSRA IN THIS FORECAST THOUGH THERE IS REASON TO
BELIEVE ISOLATED TO SCATTERED STORMS MAY DEVELOP WITH DIURNAL
HEATING.


EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCAE 260553
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
153 AM EDT SUN APR 26 2015

.SYNOPSIS...
DRIER WEATHER RETURNS FOR SUNDAY AS A COLD FRONT MOVES SOUTH ACROSS
THE REGION. THE NEXT CHANCE FOR SIGNIFICANT RAIN MOVES IN FOR THE
MIDDLE OF NEXT WEEK AS MOISTURE INCREASES AHEAD OF A LOW PRESSURE
SYSTEM COMING OUT OF THE GULF OF MEXICO.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A FRONTAL BOUNDARY IS POSITIONED JUST SOUTH OF THE NC/SC BORDER
TONIGHT. OBSERVATIONS SHOW NORTHEASTERLY WINDS NORTH OF THE
BOUNDARY AND SOUTHWESTERLY WINDS FOR A MAJORITY OF THE FORECAST
AREA WHICH IS SOUTH OF THE BOUNDARY. EXPECT ISOLATED SHOWERS AND
STORMS TO CONTINUE BEHIND THE QLCS DEPARTING OFF THE COAST. THE
HIGHEST MOISTURE IS CURRENTLY ALONG THE SOUTHERN AND EASTERN
COUNTIES. MESOANALYSIS ALSO SHOWS WEAK TO MODERATE INSTABILITY
REMAINS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WITH LIFTED
INDICES AS LOW AS -4/-5 IN THE SOUTHERNMOST PART OF THE FA. EXPECT
THIS AREA TO SEE A MAJORITY OF THE SHOWER ACTIVITY OVER THE NEXT
HOUR OR TWO. THE HRRR SEEMS TO BE HANDLING THE ACTIVITY FAIRLY
WELL AND SHOWS MOST OF THE ACTIVITY DEPARTING THE FORECAST AREA BY
06Z SO HAVE TRENDED POPS DOWN OVERNIGHT. OBSERVATIONS SHOW LOW
VISIBILITIES IN LANCASTER AND CHESTERFIELD COUNTIES CLOSE TO THE
FRONTAL BOUNDARY ALTHOUGH LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL
SOME OVERNIGHT. OVERNIGHT LOWS REMAIN MILD...ONLY FALLING INTO THE
LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
EVENING CONVECTION HAS SHIFTED EAST OF THE AREA AND DRIER AIR
ALOFT IS MOVING IN. SURFACE LOW PRESSURE IS MOVING EASTWARD ACROSS
THE NC/VA MOUNTAINS AND WILL CONTINUE TO SHIFT EAST ACROSS NC
THROUGH THE DAY. CURRENT SATELLITE IMAGERY SHOWS WIDESPREAD LIFR
STRATUS/FOG ON THE NORTHSIDE OF A NEARLY STATIONARY FRONT ACROSS
THE NORTHERN MIDLANDS. THIS FRONT AND RESTRICTIONS ARE EXPECTED TO
REMAIN NORTH OF THE TERMINALS OVERNIGHT BUT THERE HAVE BEEN SIGNS
OF POCKETS OF LOW CLOUDS DEVELOPING DUE TO NOCTURNAL COOLING AND
MOS GUIDANCE IS SUGGESTING A PERIOD OF MVFR/IFR CIGS IMPACTING THE
TERMINALS. CONFIDENCE IS LOW IN THE IFR CIGS DEVELOPING BUT WILL
CARRY A PERIOD OF MVFR CIGS 08Z-12Z. STRONG LOW LEVEL JET AROUND
35 KNOTS SHOULD PREVENT/LIMIT FOG DEVELOPMENT ALTHOUGH IT CANNOT
BE RULED OUT.

INCREASING PRESSURE GRADIENT AND STRONG LOW LEVEL WIND FIELD WILL
ALLOW STRONG MIXING TO OCCUR DURING THE DAY TODAY AND EXPECT
BREEZY WESTERLY WINDS AROUND 15 KNOTS WITH GUSTS AROUND 25 KNOTS.
STRONG INSTABILITY THIS AFTERNOON BUT LIMITED MOISTURE PRECLUDES
ANY MENTION OF TSRA IN THIS FORECAST THOUGH THERE IS REASON TO
BELIEVE ISOLATED TO SCATTERED STORMS MAY DEVELOP WITH DIURNAL
HEATING.


EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCAE 260553
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
153 AM EDT SUN APR 26 2015

.SYNOPSIS...
DRIER WEATHER RETURNS FOR SUNDAY AS A COLD FRONT MOVES SOUTH ACROSS
THE REGION. THE NEXT CHANCE FOR SIGNIFICANT RAIN MOVES IN FOR THE
MIDDLE OF NEXT WEEK AS MOISTURE INCREASES AHEAD OF A LOW PRESSURE
SYSTEM COMING OUT OF THE GULF OF MEXICO.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A FRONTAL BOUNDARY IS POSITIONED JUST SOUTH OF THE NC/SC BORDER
TONIGHT. OBSERVATIONS SHOW NORTHEASTERLY WINDS NORTH OF THE
BOUNDARY AND SOUTHWESTERLY WINDS FOR A MAJORITY OF THE FORECAST
AREA WHICH IS SOUTH OF THE BOUNDARY. EXPECT ISOLATED SHOWERS AND
STORMS TO CONTINUE BEHIND THE QLCS DEPARTING OFF THE COAST. THE
HIGHEST MOISTURE IS CURRENTLY ALONG THE SOUTHERN AND EASTERN
COUNTIES. MESOANALYSIS ALSO SHOWS WEAK TO MODERATE INSTABILITY
REMAINS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WITH LIFTED
INDICES AS LOW AS -4/-5 IN THE SOUTHERNMOST PART OF THE FA. EXPECT
THIS AREA TO SEE A MAJORITY OF THE SHOWER ACTIVITY OVER THE NEXT
HOUR OR TWO. THE HRRR SEEMS TO BE HANDLING THE ACTIVITY FAIRLY
WELL AND SHOWS MOST OF THE ACTIVITY DEPARTING THE FORECAST AREA BY
06Z SO HAVE TRENDED POPS DOWN OVERNIGHT. OBSERVATIONS SHOW LOW
VISIBILITIES IN LANCASTER AND CHESTERFIELD COUNTIES CLOSE TO THE
FRONTAL BOUNDARY ALTHOUGH LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL
SOME OVERNIGHT. OVERNIGHT LOWS REMAIN MILD...ONLY FALLING INTO THE
LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
EVENING CONVECTION HAS SHIFTED EAST OF THE AREA AND DRIER AIR
ALOFT IS MOVING IN. SURFACE LOW PRESSURE IS MOVING EASTWARD ACROSS
THE NC/VA MOUNTAINS AND WILL CONTINUE TO SHIFT EAST ACROSS NC
THROUGH THE DAY. CURRENT SATELLITE IMAGERY SHOWS WIDESPREAD LIFR
STRATUS/FOG ON THE NORTHSIDE OF A NEARLY STATIONARY FRONT ACROSS
THE NORTHERN MIDLANDS. THIS FRONT AND RESTRICTIONS ARE EXPECTED TO
REMAIN NORTH OF THE TERMINALS OVERNIGHT BUT THERE HAVE BEEN SIGNS
OF POCKETS OF LOW CLOUDS DEVELOPING DUE TO NOCTURNAL COOLING AND
MOS GUIDANCE IS SUGGESTING A PERIOD OF MVFR/IFR CIGS IMPACTING THE
TERMINALS. CONFIDENCE IS LOW IN THE IFR CIGS DEVELOPING BUT WILL
CARRY A PERIOD OF MVFR CIGS 08Z-12Z. STRONG LOW LEVEL JET AROUND
35 KNOTS SHOULD PREVENT/LIMIT FOG DEVELOPMENT ALTHOUGH IT CANNOT
BE RULED OUT.

INCREASING PRESSURE GRADIENT AND STRONG LOW LEVEL WIND FIELD WILL
ALLOW STRONG MIXING TO OCCUR DURING THE DAY TODAY AND EXPECT
BREEZY WESTERLY WINDS AROUND 15 KNOTS WITH GUSTS AROUND 25 KNOTS.
STRONG INSTABILITY THIS AFTERNOON BUT LIMITED MOISTURE PRECLUDES
ANY MENTION OF TSRA IN THIS FORECAST THOUGH THERE IS REASON TO
BELIEVE ISOLATED TO SCATTERED STORMS MAY DEVELOP WITH DIURNAL
HEATING.


EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCAE 260553
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
153 AM EDT SUN APR 26 2015

.SYNOPSIS...
DRIER WEATHER RETURNS FOR SUNDAY AS A COLD FRONT MOVES SOUTH ACROSS
THE REGION. THE NEXT CHANCE FOR SIGNIFICANT RAIN MOVES IN FOR THE
MIDDLE OF NEXT WEEK AS MOISTURE INCREASES AHEAD OF A LOW PRESSURE
SYSTEM COMING OUT OF THE GULF OF MEXICO.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A FRONTAL BOUNDARY IS POSITIONED JUST SOUTH OF THE NC/SC BORDER
TONIGHT. OBSERVATIONS SHOW NORTHEASTERLY WINDS NORTH OF THE
BOUNDARY AND SOUTHWESTERLY WINDS FOR A MAJORITY OF THE FORECAST
AREA WHICH IS SOUTH OF THE BOUNDARY. EXPECT ISOLATED SHOWERS AND
STORMS TO CONTINUE BEHIND THE QLCS DEPARTING OFF THE COAST. THE
HIGHEST MOISTURE IS CURRENTLY ALONG THE SOUTHERN AND EASTERN
COUNTIES. MESOANALYSIS ALSO SHOWS WEAK TO MODERATE INSTABILITY
REMAINS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WITH LIFTED
INDICES AS LOW AS -4/-5 IN THE SOUTHERNMOST PART OF THE FA. EXPECT
THIS AREA TO SEE A MAJORITY OF THE SHOWER ACTIVITY OVER THE NEXT
HOUR OR TWO. THE HRRR SEEMS TO BE HANDLING THE ACTIVITY FAIRLY
WELL AND SHOWS MOST OF THE ACTIVITY DEPARTING THE FORECAST AREA BY
06Z SO HAVE TRENDED POPS DOWN OVERNIGHT. OBSERVATIONS SHOW LOW
VISIBILITIES IN LANCASTER AND CHESTERFIELD COUNTIES CLOSE TO THE
FRONTAL BOUNDARY ALTHOUGH LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL
SOME OVERNIGHT. OVERNIGHT LOWS REMAIN MILD...ONLY FALLING INTO THE
LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
EVENING CONVECTION HAS SHIFTED EAST OF THE AREA AND DRIER AIR
ALOFT IS MOVING IN. SURFACE LOW PRESSURE IS MOVING EASTWARD ACROSS
THE NC/VA MOUNTAINS AND WILL CONTINUE TO SHIFT EAST ACROSS NC
THROUGH THE DAY. CURRENT SATELLITE IMAGERY SHOWS WIDESPREAD LIFR
STRATUS/FOG ON THE NORTHSIDE OF A NEARLY STATIONARY FRONT ACROSS
THE NORTHERN MIDLANDS. THIS FRONT AND RESTRICTIONS ARE EXPECTED TO
REMAIN NORTH OF THE TERMINALS OVERNIGHT BUT THERE HAVE BEEN SIGNS
OF POCKETS OF LOW CLOUDS DEVELOPING DUE TO NOCTURNAL COOLING AND
MOS GUIDANCE IS SUGGESTING A PERIOD OF MVFR/IFR CIGS IMPACTING THE
TERMINALS. CONFIDENCE IS LOW IN THE IFR CIGS DEVELOPING BUT WILL
CARRY A PERIOD OF MVFR CIGS 08Z-12Z. STRONG LOW LEVEL JET AROUND
35 KNOTS SHOULD PREVENT/LIMIT FOG DEVELOPMENT ALTHOUGH IT CANNOT
BE RULED OUT.

INCREASING PRESSURE GRADIENT AND STRONG LOW LEVEL WIND FIELD WILL
ALLOW STRONG MIXING TO OCCUR DURING THE DAY TODAY AND EXPECT
BREEZY WESTERLY WINDS AROUND 15 KNOTS WITH GUSTS AROUND 25 KNOTS.
STRONG INSTABILITY THIS AFTERNOON BUT LIMITED MOISTURE PRECLUDES
ANY MENTION OF TSRA IN THIS FORECAST THOUGH THERE IS REASON TO
BELIEVE ISOLATED TO SCATTERED STORMS MAY DEVELOP WITH DIURNAL
HEATING.


EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCAE 260553
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
153 AM EDT SUN APR 26 2015

.SYNOPSIS...
DRIER WEATHER RETURNS FOR SUNDAY AS A COLD FRONT MOVES SOUTH ACROSS
THE REGION. THE NEXT CHANCE FOR SIGNIFICANT RAIN MOVES IN FOR THE
MIDDLE OF NEXT WEEK AS MOISTURE INCREASES AHEAD OF A LOW PRESSURE
SYSTEM COMING OUT OF THE GULF OF MEXICO.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A FRONTAL BOUNDARY IS POSITIONED JUST SOUTH OF THE NC/SC BORDER
TONIGHT. OBSERVATIONS SHOW NORTHEASTERLY WINDS NORTH OF THE
BOUNDARY AND SOUTHWESTERLY WINDS FOR A MAJORITY OF THE FORECAST
AREA WHICH IS SOUTH OF THE BOUNDARY. EXPECT ISOLATED SHOWERS AND
STORMS TO CONTINUE BEHIND THE QLCS DEPARTING OFF THE COAST. THE
HIGHEST MOISTURE IS CURRENTLY ALONG THE SOUTHERN AND EASTERN
COUNTIES. MESOANALYSIS ALSO SHOWS WEAK TO MODERATE INSTABILITY
REMAINS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WITH LIFTED
INDICES AS LOW AS -4/-5 IN THE SOUTHERNMOST PART OF THE FA. EXPECT
THIS AREA TO SEE A MAJORITY OF THE SHOWER ACTIVITY OVER THE NEXT
HOUR OR TWO. THE HRRR SEEMS TO BE HANDLING THE ACTIVITY FAIRLY
WELL AND SHOWS MOST OF THE ACTIVITY DEPARTING THE FORECAST AREA BY
06Z SO HAVE TRENDED POPS DOWN OVERNIGHT. OBSERVATIONS SHOW LOW
VISIBILITIES IN LANCASTER AND CHESTERFIELD COUNTIES CLOSE TO THE
FRONTAL BOUNDARY ALTHOUGH LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL
SOME OVERNIGHT. OVERNIGHT LOWS REMAIN MILD...ONLY FALLING INTO THE
LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
EVENING CONVECTION HAS SHIFTED EAST OF THE AREA AND DRIER AIR
ALOFT IS MOVING IN. SURFACE LOW PRESSURE IS MOVING EASTWARD ACROSS
THE NC/VA MOUNTAINS AND WILL CONTINUE TO SHIFT EAST ACROSS NC
THROUGH THE DAY. CURRENT SATELLITE IMAGERY SHOWS WIDESPREAD LIFR
STRATUS/FOG ON THE NORTHSIDE OF A NEARLY STATIONARY FRONT ACROSS
THE NORTHERN MIDLANDS. THIS FRONT AND RESTRICTIONS ARE EXPECTED TO
REMAIN NORTH OF THE TERMINALS OVERNIGHT BUT THERE HAVE BEEN SIGNS
OF POCKETS OF LOW CLOUDS DEVELOPING DUE TO NOCTURNAL COOLING AND
MOS GUIDANCE IS SUGGESTING A PERIOD OF MVFR/IFR CIGS IMPACTING THE
TERMINALS. CONFIDENCE IS LOW IN THE IFR CIGS DEVELOPING BUT WILL
CARRY A PERIOD OF MVFR CIGS 08Z-12Z. STRONG LOW LEVEL JET AROUND
35 KNOTS SHOULD PREVENT/LIMIT FOG DEVELOPMENT ALTHOUGH IT CANNOT
BE RULED OUT.

INCREASING PRESSURE GRADIENT AND STRONG LOW LEVEL WIND FIELD WILL
ALLOW STRONG MIXING TO OCCUR DURING THE DAY TODAY AND EXPECT
BREEZY WESTERLY WINDS AROUND 15 KNOTS WITH GUSTS AROUND 25 KNOTS.
STRONG INSTABILITY THIS AFTERNOON BUT LIMITED MOISTURE PRECLUDES
ANY MENTION OF TSRA IN THIS FORECAST THOUGH THERE IS REASON TO
BELIEVE ISOLATED TO SCATTERED STORMS MAY DEVELOP WITH DIURNAL
HEATING.


EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KCAE 260553
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
153 AM EDT SUN APR 26 2015

.SYNOPSIS...
DRIER WEATHER RETURNS FOR SUNDAY AS A COLD FRONT MOVES SOUTH ACROSS
THE REGION. THE NEXT CHANCE FOR SIGNIFICANT RAIN MOVES IN FOR THE
MIDDLE OF NEXT WEEK AS MOISTURE INCREASES AHEAD OF A LOW PRESSURE
SYSTEM COMING OUT OF THE GULF OF MEXICO.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A FRONTAL BOUNDARY IS POSITIONED JUST SOUTH OF THE NC/SC BORDER
TONIGHT. OBSERVATIONS SHOW NORTHEASTERLY WINDS NORTH OF THE
BOUNDARY AND SOUTHWESTERLY WINDS FOR A MAJORITY OF THE FORECAST
AREA WHICH IS SOUTH OF THE BOUNDARY. EXPECT ISOLATED SHOWERS AND
STORMS TO CONTINUE BEHIND THE QLCS DEPARTING OFF THE COAST. THE
HIGHEST MOISTURE IS CURRENTLY ALONG THE SOUTHERN AND EASTERN
COUNTIES. MESOANALYSIS ALSO SHOWS WEAK TO MODERATE INSTABILITY
REMAINS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WITH LIFTED
INDICES AS LOW AS -4/-5 IN THE SOUTHERNMOST PART OF THE FA. EXPECT
THIS AREA TO SEE A MAJORITY OF THE SHOWER ACTIVITY OVER THE NEXT
HOUR OR TWO. THE HRRR SEEMS TO BE HANDLING THE ACTIVITY FAIRLY
WELL AND SHOWS MOST OF THE ACTIVITY DEPARTING THE FORECAST AREA BY
06Z SO HAVE TRENDED POPS DOWN OVERNIGHT. OBSERVATIONS SHOW LOW
VISIBILITIES IN LANCASTER AND CHESTERFIELD COUNTIES CLOSE TO THE
FRONTAL BOUNDARY ALTHOUGH LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL
SOME OVERNIGHT. OVERNIGHT LOWS REMAIN MILD...ONLY FALLING INTO THE
LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
EVENING CONVECTION HAS SHIFTED EAST OF THE AREA AND DRIER AIR
ALOFT IS MOVING IN. SURFACE LOW PRESSURE IS MOVING EASTWARD ACROSS
THE NC/VA MOUNTAINS AND WILL CONTINUE TO SHIFT EAST ACROSS NC
THROUGH THE DAY. CURRENT SATELLITE IMAGERY SHOWS WIDESPREAD LIFR
STRATUS/FOG ON THE NORTHSIDE OF A NEARLY STATIONARY FRONT ACROSS
THE NORTHERN MIDLANDS. THIS FRONT AND RESTRICTIONS ARE EXPECTED TO
REMAIN NORTH OF THE TERMINALS OVERNIGHT BUT THERE HAVE BEEN SIGNS
OF POCKETS OF LOW CLOUDS DEVELOPING DUE TO NOCTURNAL COOLING AND
MOS GUIDANCE IS SUGGESTING A PERIOD OF MVFR/IFR CIGS IMPACTING THE
TERMINALS. CONFIDENCE IS LOW IN THE IFR CIGS DEVELOPING BUT WILL
CARRY A PERIOD OF MVFR CIGS 08Z-12Z. STRONG LOW LEVEL JET AROUND
35 KNOTS SHOULD PREVENT/LIMIT FOG DEVELOPMENT ALTHOUGH IT CANNOT
BE RULED OUT.

INCREASING PRESSURE GRADIENT AND STRONG LOW LEVEL WIND FIELD WILL
ALLOW STRONG MIXING TO OCCUR DURING THE DAY TODAY AND EXPECT
BREEZY WESTERLY WINDS AROUND 15 KNOTS WITH GUSTS AROUND 25 KNOTS.
STRONG INSTABILITY THIS AFTERNOON BUT LIMITED MOISTURE PRECLUDES
ANY MENTION OF TSRA IN THIS FORECAST THOUGH THERE IS REASON TO
BELIEVE ISOLATED TO SCATTERED STORMS MAY DEVELOP WITH DIURNAL
HEATING.


EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCHS 260547
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
147 AM EDT SUN APR 26 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OTHERWISE RAIN-FREE CONDITIONS ARE EXPECTED THE REMAINDER OF THE
NIGHT AS SUBSIDENCE DEVELOPS IN WAKE OF A DEPARTING SHORT WAVE.
SKIES WILL CONTINUE TO CLEAR OVERNIGHT...EXCEPT SOME LOW STRATUS
COULD DEVELOP AROUND DAYBREAK DUE TO MOIST SOILS AND THE PRESENCE
OF A SUBSIDENCE INVERSION. LOWS HAVE ALREADY BEEN REACHED IN RAIN
COOLED AIR IN SOME LOCATIONS...SO NON-DIURNAL TEMPERATURE CURVES
ARE EXPECTED. OVERALL TEMPERATURES SHOULD BE IN THE MID TO UPPER
60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
LOW STRATUS COULD DEVELOP AROUND DAYBREAK AT THE TERMINALS DUE TO
LINGERING LOW LEVEL MOISTURE...WET GROUND CONDITIONS AND A
SUBSIDENCE INVERSION...POSSIBLY RESULTING IN MVFR OR LOWER
CONDITIONS FOR A FEW HOURS. OTHERWISE...VFR CONDITIONS ARE
EXPECTED TO PREVAIL. A POTENT 35-40 KT LOW LEVEL JET AT 2K FT WILL
RESULT IN SOME LOW WIND SHEAR AT THE TERMINALS THROUGH ABOUT
1330Z. ONCE THE INVERSION LIFTS AND MIXING COMMENCES IN THE
MORNING...THE STRONGER WINDS ALOFT WILL MIX DOWN IN THE FORM OF
HIGHER GUSTS...WHICH COULD PEAK UPWARDS OF 25-30 KT IN THE
AFTERNOON WHEN THE DEEPEST MIXING WILL OCCUR. A BACKDOOR COLD
FRONT WILL DROP IN FROM THE NORTH THIS EVENING...AND COULD PRODUCE
SOME ISOLATED SHOWERS AND THUNDERSTORMS AROUND KCHS IN THE 22-03Z
TIME FRAME...AND VICINITY THUNDERSTORMS HAVE BEEN ADDED TO THE TAF
ACCORDINGLY.

EXTENDED AVIATION OUTLOOK...VFR CONDITIONS SHOULD PREVAIL INTO
TUESDAY BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TONIGHT...MODEST SOUTH/SOUTHWEST WINDS WILL PERSIST OVERNIGHT
WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25 KT OFFSHORE
WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE GEORGIA
OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4 FT NEARSHORE
WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...JAQ
SHORT TERM...
LONG TERM...
AVIATION...JAQ
MARINE...



000
FXUS62 KCHS 260547
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
147 AM EDT SUN APR 26 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OTHERWISE RAIN-FREE CONDITIONS ARE EXPECTED THE REMAINDER OF THE
NIGHT AS SUBSIDENCE DEVELOPS IN WAKE OF A DEPARTING SHORT WAVE.
SKIES WILL CONTINUE TO CLEAR OVERNIGHT...EXCEPT SOME LOW STRATUS
COULD DEVELOP AROUND DAYBREAK DUE TO MOIST SOILS AND THE PRESENCE
OF A SUBSIDENCE INVERSION. LOWS HAVE ALREADY BEEN REACHED IN RAIN
COOLED AIR IN SOME LOCATIONS...SO NON-DIURNAL TEMPERATURE CURVES
ARE EXPECTED. OVERALL TEMPERATURES SHOULD BE IN THE MID TO UPPER
60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
LOW STRATUS COULD DEVELOP AROUND DAYBREAK AT THE TERMINALS DUE TO
LINGERING LOW LEVEL MOISTURE...WET GROUND CONDITIONS AND A
SUBSIDENCE INVERSION...POSSIBLY RESULTING IN MVFR OR LOWER
CONDITIONS FOR A FEW HOURS. OTHERWISE...VFR CONDITIONS ARE
EXPECTED TO PREVAIL. A POTENT 35-40 KT LOW LEVEL JET AT 2K FT WILL
RESULT IN SOME LOW WIND SHEAR AT THE TERMINALS THROUGH ABOUT
1330Z. ONCE THE INVERSION LIFTS AND MIXING COMMENCES IN THE
MORNING...THE STRONGER WINDS ALOFT WILL MIX DOWN IN THE FORM OF
HIGHER GUSTS...WHICH COULD PEAK UPWARDS OF 25-30 KT IN THE
AFTERNOON WHEN THE DEEPEST MIXING WILL OCCUR. A BACKDOOR COLD
FRONT WILL DROP IN FROM THE NORTH THIS EVENING...AND COULD PRODUCE
SOME ISOLATED SHOWERS AND THUNDERSTORMS AROUND KCHS IN THE 22-03Z
TIME FRAME...AND VICINITY THUNDERSTORMS HAVE BEEN ADDED TO THE TAF
ACCORDINGLY.

EXTENDED AVIATION OUTLOOK...VFR CONDITIONS SHOULD PREVAIL INTO
TUESDAY BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TONIGHT...MODEST SOUTH/SOUTHWEST WINDS WILL PERSIST OVERNIGHT
WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25 KT OFFSHORE
WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE GEORGIA
OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4 FT NEARSHORE
WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...JAQ
SHORT TERM...
LONG TERM...
AVIATION...JAQ
MARINE...




000
FXUS62 KCHS 260445
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1245 AM EDT SUN APR 26 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
QLCS CONTINUES TO PUSH WELL OFFSHORE EARLY THIS MORNING. A BATCH
OF MAINLY LIGHT SHOWERS WILL CONTINUE TO PUSH THROUGH 130
AM...OTHERWISE RAIN-FREE CONDITIONS ARE EXPECTED THE REMAINDER OF
THE NIGHT AS SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT
WAVE. SKIES WILL CONTINUE TO CLEAR OVERNIGHT...BUT SOME LOW
STRATUS COULD DEVELOP AROUND DAYBREAK DUE TO MOIST SOILS AND THE
PRESENCE OF A SUBSIDENCE INVERSION. LOWS HAVE ALREADY BEEN REACHED
IN RAIN COOLED AIR IN SOME LOCATIONS...SO NON-DIURNAL TEMPERATURE
CURVES ARE EXPECTED. OVERALL TEMPERATURES SHOULD BE IN THE MID TO
UPPER 60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SOME LOW STRATUS COULD DEVELOP AROUND DAYBREAK DUE TO LINGERING
LOW LEVEL MOISTURE...WET GROUND AND A SUBSIDENCE
INVERSION...POSSIBLY RESULTING IN MVFR OR LOWER CONDITIONS FOR A
FEW HOURS. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREVAIL.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...MODEST SOUTH/SOUTHWEST WINDS WILL PERSIST OVERNIGHT
WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25 KT OFFSHORE
WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE GEORGIA
OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4 FT NEARSHORE
WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ374.

&&

$$

NEAR TERM...JAQ
SHORT TERM...
LONG TERM...
AVIATION...JAQ
MARINE...




000
FXUS62 KCHS 260445
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1245 AM EDT SUN APR 26 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
QLCS CONTINUES TO PUSH WELL OFFSHORE EARLY THIS MORNING. A BATCH
OF MAINLY LIGHT SHOWERS WILL CONTINUE TO PUSH THROUGH 130
AM...OTHERWISE RAIN-FREE CONDITIONS ARE EXPECTED THE REMAINDER OF
THE NIGHT AS SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT
WAVE. SKIES WILL CONTINUE TO CLEAR OVERNIGHT...BUT SOME LOW
STRATUS COULD DEVELOP AROUND DAYBREAK DUE TO MOIST SOILS AND THE
PRESENCE OF A SUBSIDENCE INVERSION. LOWS HAVE ALREADY BEEN REACHED
IN RAIN COOLED AIR IN SOME LOCATIONS...SO NON-DIURNAL TEMPERATURE
CURVES ARE EXPECTED. OVERALL TEMPERATURES SHOULD BE IN THE MID TO
UPPER 60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SOME LOW STRATUS COULD DEVELOP AROUND DAYBREAK DUE TO LINGERING
LOW LEVEL MOISTURE...WET GROUND AND A SUBSIDENCE
INVERSION...POSSIBLY RESULTING IN MVFR OR LOWER CONDITIONS FOR A
FEW HOURS. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREVAIL.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...MODEST SOUTH/SOUTHWEST WINDS WILL PERSIST OVERNIGHT
WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25 KT OFFSHORE
WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE GEORGIA
OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4 FT NEARSHORE
WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ374.

&&

$$

NEAR TERM...JAQ
SHORT TERM...
LONG TERM...
AVIATION...JAQ
MARINE...




000
FXUS62 KCHS 260445
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1245 AM EDT SUN APR 26 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
QLCS CONTINUES TO PUSH WELL OFFSHORE EARLY THIS MORNING. A BATCH
OF MAINLY LIGHT SHOWERS WILL CONTINUE TO PUSH THROUGH 130
AM...OTHERWISE RAIN-FREE CONDITIONS ARE EXPECTED THE REMAINDER OF
THE NIGHT AS SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT
WAVE. SKIES WILL CONTINUE TO CLEAR OVERNIGHT...BUT SOME LOW
STRATUS COULD DEVELOP AROUND DAYBREAK DUE TO MOIST SOILS AND THE
PRESENCE OF A SUBSIDENCE INVERSION. LOWS HAVE ALREADY BEEN REACHED
IN RAIN COOLED AIR IN SOME LOCATIONS...SO NON-DIURNAL TEMPERATURE
CURVES ARE EXPECTED. OVERALL TEMPERATURES SHOULD BE IN THE MID TO
UPPER 60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SOME LOW STRATUS COULD DEVELOP AROUND DAYBREAK DUE TO LINGERING
LOW LEVEL MOISTURE...WET GROUND AND A SUBSIDENCE
INVERSION...POSSIBLY RESULTING IN MVFR OR LOWER CONDITIONS FOR A
FEW HOURS. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREVAIL.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...MODEST SOUTH/SOUTHWEST WINDS WILL PERSIST OVERNIGHT
WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25 KT OFFSHORE
WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE GEORGIA
OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4 FT NEARSHORE
WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ374.

&&

$$

NEAR TERM...JAQ
SHORT TERM...
LONG TERM...
AVIATION...JAQ
MARINE...




000
FXUS62 KCHS 260445
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1245 AM EDT SUN APR 26 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
QLCS CONTINUES TO PUSH WELL OFFSHORE EARLY THIS MORNING. A BATCH
OF MAINLY LIGHT SHOWERS WILL CONTINUE TO PUSH THROUGH 130
AM...OTHERWISE RAIN-FREE CONDITIONS ARE EXPECTED THE REMAINDER OF
THE NIGHT AS SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT
WAVE. SKIES WILL CONTINUE TO CLEAR OVERNIGHT...BUT SOME LOW
STRATUS COULD DEVELOP AROUND DAYBREAK DUE TO MOIST SOILS AND THE
PRESENCE OF A SUBSIDENCE INVERSION. LOWS HAVE ALREADY BEEN REACHED
IN RAIN COOLED AIR IN SOME LOCATIONS...SO NON-DIURNAL TEMPERATURE
CURVES ARE EXPECTED. OVERALL TEMPERATURES SHOULD BE IN THE MID TO
UPPER 60S.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SOME LOW STRATUS COULD DEVELOP AROUND DAYBREAK DUE TO LINGERING
LOW LEVEL MOISTURE...WET GROUND AND A SUBSIDENCE
INVERSION...POSSIBLY RESULTING IN MVFR OR LOWER CONDITIONS FOR A
FEW HOURS. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREVAIL.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...MODEST SOUTH/SOUTHWEST WINDS WILL PERSIST OVERNIGHT
WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25 KT OFFSHORE
WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE GEORGIA
OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4 FT NEARSHORE
WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR AMZ374.

&&

$$

NEAR TERM...JAQ
SHORT TERM...
LONG TERM...
AVIATION...JAQ
MARINE...




000
FXUS62 KGSP 260250
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1050 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 1045 PM EDT SATURDAY...UPSTREAM CONVECTION ACROSS SE/SC
KENTUCKY CONTINUES TO SLIDE SOUTHEAST ALONG AN INSTABILITY AXIS
THROUGH MIDDLE TN.  LATEST HRRR CONTINUES TO INDICATE SURVIVAL OF
SAID CONVECTIVE LINE AS IT APPROACHES THE NC HIGH TERRAIN ALONG THE
TN STATE LINE.  A SHARP INSTABILITY GRADIENT ACROSS EXTREME EASTERN
TN WILL CONTINUE TO FUEL THUNDERSTORMS THROUGH AT LEAST
MIDNIGHT...BEFORE IMPACTING THE MTNS AROUND 2AM WHEN QUICK WEAKENING
OF ACTIVITY IS EXPECTED.  THUS...THINK CURRENT POP TRENDS REMAIN
VALID AND OPTED NOT TO MAKE ANY ADJUSTMENTS.  WILL ALSO CONTINUE TO
NOTE THAT AN ABUNDANCE OF GUIDANCE FAVORS AT LEAST PATCHY DENSE FOG
ACROSS THE NC/SC PIEDMONT ALONG THE I77 CORRIDOR OVERNIGHT.  THUS A
DFA MAY BE NEEDED LATER.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
AT KCLT...INITIALIZED TAF MVFR AS CURRENT IFR RESTRICTIONS SHOULD
IMPROVE SHORTLY.  ADDED TSRA TEMPO FROM 07Z-10Z TO ACCOUNT FOR
UPSTREAM MCS PROPAGATION/SURVIVAL THROUGH THE MOUNTAINS AS SHOWN ON
THE LATEST HRRR.  HOWEVER...IF THIS TRACK DOES PAN OUT...LITTLE TO
NO INSTABILITY WILL BE AVAILABLE FOR CONVECTION THUS ANY STRONG TSRA
IS LIKELY RULED OUT.  ACTUALLY WOULDNT BE SURPRISED IF ITS NOTHING
MORE THAN A FEW SHOWERS.  OTHERWISE...GUIDANCE CONTINUES TO FAVOR
PATCHY DENSE FOG AROUND THE LOWER NC PIEDMONT BY MORNING THUS ADDED
FM GROUP TO INDICATE IFR RESTRICTIONS.  IMPROVED TAF TO LOW VFR
AROUND 15Z WITH NORTHERLY WINDS PREVAILING AHEAD OF A PROB30 IN THE
AFTN FOR POSSIBLE CONVECTION ALONG SLOW MOVING FRONTAL AXIS.

ELSEWHERE...MODELS STILL FAVOR PROLONGED LIFR/IFR RESTRICTIONS AT
KHKY THUS TAF REFLECTS SUCH.  OTHERWISE...ALL TAFS INITIALIZE VFR
THROUGH THE EARLY EVENING HOURS.  MCS SLIDING THROUGH CENTRAL KY AT
THIS TIME IS PROGGED TO ADVANCE THROUGH THE PLATEAU INTO THE HIGH
TERRAIN OF WESTERN NC AFTER MIDNIGHT.  SOME CAM SOLUTIONS INDICATE
SURVIVAL OF SAID MCS THROUGH THE MOUNTAINS.  THUS...TAFS FEATURE
VCTS MENTION TO ACCOUNT FOR ANY ENHANCED CONVECTION.  AS WITH KCLT
ABOVE...EXPECTING INSTABILITY TO BE AT A PREMIUM...ESPECIALLY EAST
OF THE MTNS THEREFORE NO ROBUST CONVECTION IS EXPECTED.  WITH THAT
LOWERED ALL SITES TO EITHER LOW VFR OR MVFR AMIDST LIGHT/MODERATE
NORTHERLY WINDS.  DID INCLUDE EARLY MORNING PATCHY FOG AT ALL SITES
WITH SOME ISOLATED DENSE FOG EXPECTED OVER THE NC PIEDMONT...THUS DO
CARRY 1/2SM AT KHKY.  OTHERWISE CONDITIONS WILL IMPROVE THROUGH
MORNING WITH SHRA/TSRA EXITING THE REGION...IF PRESENT.  DID
REINTRODUCE WX MENTION LATE IN THE PERIOD TO ACCOUNT FOR SLOW MOVING
FRONTAL AXIS ON SUNDAY AFTERNOON/EVENING.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON SUNDAY THEN
FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW PRESSURE
SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND THURSDAY.

CONFIDENCE TABLE...

            02-08Z        08-14Z        14-20Z        20-00Z
KCLT       HIGH  95%     MED   69%     HIGH  86%     MED   70%
KGSP       MED   75%     HIGH  89%     HIGH  98%     HIGH  80%
KAVL       HIGH 100%     HIGH 100%     HIGH  94%     HIGH  90%
KHKY       MED   75%     MED   74%     LOW   56%     MED   77%
KGMU       MED   76%     HIGH  94%     HIGH  98%     HIGH  95%
KAND       MED   79%     HIGH  94%     HIGH  94%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...CDG/JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...CDG




000
FXUS62 KGSP 260250
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1050 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 1045 PM EDT SATURDAY...UPSTREAM CONVECTION ACROSS SE/SC
KENTUCKY CONTINUES TO SLIDE SOUTHEAST ALONG AN INSTABILITY AXIS
THROUGH MIDDLE TN.  LATEST HRRR CONTINUES TO INDICATE SURVIVAL OF
SAID CONVECTIVE LINE AS IT APPROACHES THE NC HIGH TERRAIN ALONG THE
TN STATE LINE.  A SHARP INSTABILITY GRADIENT ACROSS EXTREME EASTERN
TN WILL CONTINUE TO FUEL THUNDERSTORMS THROUGH AT LEAST
MIDNIGHT...BEFORE IMPACTING THE MTNS AROUND 2AM WHEN QUICK WEAKENING
OF ACTIVITY IS EXPECTED.  THUS...THINK CURRENT POP TRENDS REMAIN
VALID AND OPTED NOT TO MAKE ANY ADJUSTMENTS.  WILL ALSO CONTINUE TO
NOTE THAT AN ABUNDANCE OF GUIDANCE FAVORS AT LEAST PATCHY DENSE FOG
ACROSS THE NC/SC PIEDMONT ALONG THE I77 CORRIDOR OVERNIGHT.  THUS A
DFA MAY BE NEEDED LATER.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
AT KCLT...INITIALIZED TAF MVFR AS CURRENT IFR RESTRICTIONS SHOULD
IMPROVE SHORTLY.  ADDED TSRA TEMPO FROM 07Z-10Z TO ACCOUNT FOR
UPSTREAM MCS PROPAGATION/SURVIVAL THROUGH THE MOUNTAINS AS SHOWN ON
THE LATEST HRRR.  HOWEVER...IF THIS TRACK DOES PAN OUT...LITTLE TO
NO INSTABILITY WILL BE AVAILABLE FOR CONVECTION THUS ANY STRONG TSRA
IS LIKELY RULED OUT.  ACTUALLY WOULDNT BE SURPRISED IF ITS NOTHING
MORE THAN A FEW SHOWERS.  OTHERWISE...GUIDANCE CONTINUES TO FAVOR
PATCHY DENSE FOG AROUND THE LOWER NC PIEDMONT BY MORNING THUS ADDED
FM GROUP TO INDICATE IFR RESTRICTIONS.  IMPROVED TAF TO LOW VFR
AROUND 15Z WITH NORTHERLY WINDS PREVAILING AHEAD OF A PROB30 IN THE
AFTN FOR POSSIBLE CONVECTION ALONG SLOW MOVING FRONTAL AXIS.

ELSEWHERE...MODELS STILL FAVOR PROLONGED LIFR/IFR RESTRICTIONS AT
KHKY THUS TAF REFLECTS SUCH.  OTHERWISE...ALL TAFS INITIALIZE VFR
THROUGH THE EARLY EVENING HOURS.  MCS SLIDING THROUGH CENTRAL KY AT
THIS TIME IS PROGGED TO ADVANCE THROUGH THE PLATEAU INTO THE HIGH
TERRAIN OF WESTERN NC AFTER MIDNIGHT.  SOME CAM SOLUTIONS INDICATE
SURVIVAL OF SAID MCS THROUGH THE MOUNTAINS.  THUS...TAFS FEATURE
VCTS MENTION TO ACCOUNT FOR ANY ENHANCED CONVECTION.  AS WITH KCLT
ABOVE...EXPECTING INSTABILITY TO BE AT A PREMIUM...ESPECIALLY EAST
OF THE MTNS THEREFORE NO ROBUST CONVECTION IS EXPECTED.  WITH THAT
LOWERED ALL SITES TO EITHER LOW VFR OR MVFR AMIDST LIGHT/MODERATE
NORTHERLY WINDS.  DID INCLUDE EARLY MORNING PATCHY FOG AT ALL SITES
WITH SOME ISOLATED DENSE FOG EXPECTED OVER THE NC PIEDMONT...THUS DO
CARRY 1/2SM AT KHKY.  OTHERWISE CONDITIONS WILL IMPROVE THROUGH
MORNING WITH SHRA/TSRA EXITING THE REGION...IF PRESENT.  DID
REINTRODUCE WX MENTION LATE IN THE PERIOD TO ACCOUNT FOR SLOW MOVING
FRONTAL AXIS ON SUNDAY AFTERNOON/EVENING.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON SUNDAY THEN
FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW PRESSURE
SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND THURSDAY.

CONFIDENCE TABLE...

            02-08Z        08-14Z        14-20Z        20-00Z
KCLT       HIGH  95%     MED   69%     HIGH  86%     MED   70%
KGSP       MED   75%     HIGH  89%     HIGH  98%     HIGH  80%
KAVL       HIGH 100%     HIGH 100%     HIGH  94%     HIGH  90%
KHKY       MED   75%     MED   74%     LOW   56%     MED   77%
KGMU       MED   76%     HIGH  94%     HIGH  98%     HIGH  95%
KAND       MED   79%     HIGH  94%     HIGH  94%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...CDG/JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...CDG



000
FXUS62 KCAE 260241
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1041 PM EDT SAT APR 25 2015

.SYNOPSIS...
DRIER WEATHER RETURNS FOR SUNDAY AS A COLD FRONT MOVES SOUTH ACROSS
THE REGION. THE NEXT CHANCE FOR SIGNIFICANT RAIN MOVES IN FOR THE
MIDDLE OF NEXT WEEK AS MOISTURE INCREASES AHEAD OF A LOW PRESSURE
SYSTEM COMING OUT OF THE GULF OF MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A FRONTAL BOUNDARY IS POSITIONED JUST SOUTH OF THE NC/SC BORDER
TONIGHT. OBSERVATIONS SHOW NORTHEASTERLY WINDS NORTH OF THE
BOUNDARY AND SOUTHWESTERLY WINDS FOR A MAJORITY OF THE FORECAST
AREA WHICH IS SOUTH OF THE BOUNDARY. EXPECT ISOLATED SHOWERS AND
STORMS TO CONTINUE BEHIND THE QLCS DEPARTING OFF THE COAST. THE
HIGHEST MOISTURE IS CURRENTLY ALONG THE SOUTHERN AND EASTERN
COUNTIES. MESOANALYSIS ALSO SHOWS WEAK TO MODERATE INSTABILITY
REMAINS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WITH LIFTED
INDICES AS LOW AS -4/-5 IN THE SOUTHERNMOST PART OF THE FA. EXPECT
THIS AREA TO SEE A MAJORITY OF THE SHOWER ACTIVITY OVER THE NEXT
HOUR OR TWO. THE HRRR SEEMS TO BE HANDLING THE ACTIVITY FAIRLY
WELL AND SHOWS MOST OF THE ACTIVITY DEPARTING THE FORECAST AREA BY
06Z SO HAVE TRENDED POPS DOWN OVERNIGHT. OBSERVATIONS SHOW LOW
VISIBILITIES IN LANCASTER AND CHESTERFIELD COUNTIES CLOSE TO THE
FRONTAL BOUNDARY ALTHOUGH LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL
SOME OVERNIGHT. OVERNIGHT LOWS REMAIN MILD...ONLY FALLING INTO THE
LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
THE MAIN LINE OF SHOWERS AND STORMS HAS SHIFTED OFF THE COAST
TONIGHT WITH ISOLATED ACTIVITY REMAINING ACROSS THE SOUTHEASTERN PORTION
OF THE FORECAST AREA. NO RESTRICTIONS AT THE TAF SITES CURRENTLY
BUT CANNOT RULE OUT A SHOWER OR STORM AFFECTING AGS/DNL SO HAVE
HAVE A TEMPO GROUP THROUGH 03Z. MODELS INDICATE POTENTIAL FOR
RESTRICTIONS RETURNING AFTER 06Z ALTHOUGH BELIEVE LOW LEVEL JET
WILL LIMIT FOG POTENTIAL. HAVE ADDED MVFR RESTRICTIONS AT AGS/DNL
TOWARDS DAYBREAK ALTHOUGH CONFIDENCE IS LOW AT THIS TIME. THE LOW-
LEVEL JET SUPPORTS KEEPING LLWS IN THE TERMINAL FORECASTS
OVERNIGHT. USED THE NAM FOR THE MAGNITUDE OF THE SHEAR. THE MODELS
SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY BUT WITH SHALLOW
MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED TOO LOW TO
INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS LAMP AND THE
NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND GUSTS NEAR 24
KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCAE 260241
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1041 PM EDT SAT APR 25 2015

.SYNOPSIS...
DRIER WEATHER RETURNS FOR SUNDAY AS A COLD FRONT MOVES SOUTH ACROSS
THE REGION. THE NEXT CHANCE FOR SIGNIFICANT RAIN MOVES IN FOR THE
MIDDLE OF NEXT WEEK AS MOISTURE INCREASES AHEAD OF A LOW PRESSURE
SYSTEM COMING OUT OF THE GULF OF MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A FRONTAL BOUNDARY IS POSITIONED JUST SOUTH OF THE NC/SC BORDER
TONIGHT. OBSERVATIONS SHOW NORTHEASTERLY WINDS NORTH OF THE
BOUNDARY AND SOUTHWESTERLY WINDS FOR A MAJORITY OF THE FORECAST
AREA WHICH IS SOUTH OF THE BOUNDARY. EXPECT ISOLATED SHOWERS AND
STORMS TO CONTINUE BEHIND THE QLCS DEPARTING OFF THE COAST. THE
HIGHEST MOISTURE IS CURRENTLY ALONG THE SOUTHERN AND EASTERN
COUNTIES. MESOANALYSIS ALSO SHOWS WEAK TO MODERATE INSTABILITY
REMAINS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WITH LIFTED
INDICES AS LOW AS -4/-5 IN THE SOUTHERNMOST PART OF THE FA. EXPECT
THIS AREA TO SEE A MAJORITY OF THE SHOWER ACTIVITY OVER THE NEXT
HOUR OR TWO. THE HRRR SEEMS TO BE HANDLING THE ACTIVITY FAIRLY
WELL AND SHOWS MOST OF THE ACTIVITY DEPARTING THE FORECAST AREA BY
06Z SO HAVE TRENDED POPS DOWN OVERNIGHT. OBSERVATIONS SHOW LOW
VISIBILITIES IN LANCASTER AND CHESTERFIELD COUNTIES CLOSE TO THE
FRONTAL BOUNDARY ALTHOUGH LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL
SOME OVERNIGHT. OVERNIGHT LOWS REMAIN MILD...ONLY FALLING INTO THE
LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
THE MAIN LINE OF SHOWERS AND STORMS HAS SHIFTED OFF THE COAST
TONIGHT WITH ISOLATED ACTIVITY REMAINING ACROSS THE SOUTHEASTERN PORTION
OF THE FORECAST AREA. NO RESTRICTIONS AT THE TAF SITES CURRENTLY
BUT CANNOT RULE OUT A SHOWER OR STORM AFFECTING AGS/DNL SO HAVE
HAVE A TEMPO GROUP THROUGH 03Z. MODELS INDICATE POTENTIAL FOR
RESTRICTIONS RETURNING AFTER 06Z ALTHOUGH BELIEVE LOW LEVEL JET
WILL LIMIT FOG POTENTIAL. HAVE ADDED MVFR RESTRICTIONS AT AGS/DNL
TOWARDS DAYBREAK ALTHOUGH CONFIDENCE IS LOW AT THIS TIME. THE LOW-
LEVEL JET SUPPORTS KEEPING LLWS IN THE TERMINAL FORECASTS
OVERNIGHT. USED THE NAM FOR THE MAGNITUDE OF THE SHEAR. THE MODELS
SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY BUT WITH SHALLOW
MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED TOO LOW TO
INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS LAMP AND THE
NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND GUSTS NEAR 24
KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCAE 260241
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1041 PM EDT SAT APR 25 2015

.SYNOPSIS...
DRIER WEATHER RETURNS FOR SUNDAY AS A COLD FRONT MOVES SOUTH ACROSS
THE REGION. THE NEXT CHANCE FOR SIGNIFICANT RAIN MOVES IN FOR THE
MIDDLE OF NEXT WEEK AS MOISTURE INCREASES AHEAD OF A LOW PRESSURE
SYSTEM COMING OUT OF THE GULF OF MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A FRONTAL BOUNDARY IS POSITIONED JUST SOUTH OF THE NC/SC BORDER
TONIGHT. OBSERVATIONS SHOW NORTHEASTERLY WINDS NORTH OF THE
BOUNDARY AND SOUTHWESTERLY WINDS FOR A MAJORITY OF THE FORECAST
AREA WHICH IS SOUTH OF THE BOUNDARY. EXPECT ISOLATED SHOWERS AND
STORMS TO CONTINUE BEHIND THE QLCS DEPARTING OFF THE COAST. THE
HIGHEST MOISTURE IS CURRENTLY ALONG THE SOUTHERN AND EASTERN
COUNTIES. MESOANALYSIS ALSO SHOWS WEAK TO MODERATE INSTABILITY
REMAINS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WITH LIFTED
INDICES AS LOW AS -4/-5 IN THE SOUTHERNMOST PART OF THE FA. EXPECT
THIS AREA TO SEE A MAJORITY OF THE SHOWER ACTIVITY OVER THE NEXT
HOUR OR TWO. THE HRRR SEEMS TO BE HANDLING THE ACTIVITY FAIRLY
WELL AND SHOWS MOST OF THE ACTIVITY DEPARTING THE FORECAST AREA BY
06Z SO HAVE TRENDED POPS DOWN OVERNIGHT. OBSERVATIONS SHOW LOW
VISIBILITIES IN LANCASTER AND CHESTERFIELD COUNTIES CLOSE TO THE
FRONTAL BOUNDARY ALTHOUGH LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL
SOME OVERNIGHT. OVERNIGHT LOWS REMAIN MILD...ONLY FALLING INTO THE
LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
THE MAIN LINE OF SHOWERS AND STORMS HAS SHIFTED OFF THE COAST
TONIGHT WITH ISOLATED ACTIVITY REMAINING ACROSS THE SOUTHEASTERN PORTION
OF THE FORECAST AREA. NO RESTRICTIONS AT THE TAF SITES CURRENTLY
BUT CANNOT RULE OUT A SHOWER OR STORM AFFECTING AGS/DNL SO HAVE
HAVE A TEMPO GROUP THROUGH 03Z. MODELS INDICATE POTENTIAL FOR
RESTRICTIONS RETURNING AFTER 06Z ALTHOUGH BELIEVE LOW LEVEL JET
WILL LIMIT FOG POTENTIAL. HAVE ADDED MVFR RESTRICTIONS AT AGS/DNL
TOWARDS DAYBREAK ALTHOUGH CONFIDENCE IS LOW AT THIS TIME. THE LOW-
LEVEL JET SUPPORTS KEEPING LLWS IN THE TERMINAL FORECASTS
OVERNIGHT. USED THE NAM FOR THE MAGNITUDE OF THE SHEAR. THE MODELS
SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY BUT WITH SHALLOW
MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED TOO LOW TO
INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS LAMP AND THE
NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND GUSTS NEAR 24
KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCAE 260241
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1041 PM EDT SAT APR 25 2015

.SYNOPSIS...
DRIER WEATHER RETURNS FOR SUNDAY AS A COLD FRONT MOVES SOUTH ACROSS
THE REGION. THE NEXT CHANCE FOR SIGNIFICANT RAIN MOVES IN FOR THE
MIDDLE OF NEXT WEEK AS MOISTURE INCREASES AHEAD OF A LOW PRESSURE
SYSTEM COMING OUT OF THE GULF OF MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A FRONTAL BOUNDARY IS POSITIONED JUST SOUTH OF THE NC/SC BORDER
TONIGHT. OBSERVATIONS SHOW NORTHEASTERLY WINDS NORTH OF THE
BOUNDARY AND SOUTHWESTERLY WINDS FOR A MAJORITY OF THE FORECAST
AREA WHICH IS SOUTH OF THE BOUNDARY. EXPECT ISOLATED SHOWERS AND
STORMS TO CONTINUE BEHIND THE QLCS DEPARTING OFF THE COAST. THE
HIGHEST MOISTURE IS CURRENTLY ALONG THE SOUTHERN AND EASTERN
COUNTIES. MESOANALYSIS ALSO SHOWS WEAK TO MODERATE INSTABILITY
REMAINS ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WITH LIFTED
INDICES AS LOW AS -4/-5 IN THE SOUTHERNMOST PART OF THE FA. EXPECT
THIS AREA TO SEE A MAJORITY OF THE SHOWER ACTIVITY OVER THE NEXT
HOUR OR TWO. THE HRRR SEEMS TO BE HANDLING THE ACTIVITY FAIRLY
WELL AND SHOWS MOST OF THE ACTIVITY DEPARTING THE FORECAST AREA BY
06Z SO HAVE TRENDED POPS DOWN OVERNIGHT. OBSERVATIONS SHOW LOW
VISIBILITIES IN LANCASTER AND CHESTERFIELD COUNTIES CLOSE TO THE
FRONTAL BOUNDARY ALTHOUGH LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL
SOME OVERNIGHT. OVERNIGHT LOWS REMAIN MILD...ONLY FALLING INTO THE
LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
THE MAIN LINE OF SHOWERS AND STORMS HAS SHIFTED OFF THE COAST
TONIGHT WITH ISOLATED ACTIVITY REMAINING ACROSS THE SOUTHEASTERN PORTION
OF THE FORECAST AREA. NO RESTRICTIONS AT THE TAF SITES CURRENTLY
BUT CANNOT RULE OUT A SHOWER OR STORM AFFECTING AGS/DNL SO HAVE
HAVE A TEMPO GROUP THROUGH 03Z. MODELS INDICATE POTENTIAL FOR
RESTRICTIONS RETURNING AFTER 06Z ALTHOUGH BELIEVE LOW LEVEL JET
WILL LIMIT FOG POTENTIAL. HAVE ADDED MVFR RESTRICTIONS AT AGS/DNL
TOWARDS DAYBREAK ALTHOUGH CONFIDENCE IS LOW AT THIS TIME. THE LOW-
LEVEL JET SUPPORTS KEEPING LLWS IN THE TERMINAL FORECASTS
OVERNIGHT. USED THE NAM FOR THE MAGNITUDE OF THE SHEAR. THE MODELS
SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY BUT WITH SHALLOW
MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED TOO LOW TO
INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS LAMP AND THE
NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND GUSTS NEAR 24
KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCHS 260151
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
951 PM EDT SAT APR 25 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SEVERE QLCS WITH A HISTORY OF PRODUCING WIDESPREAD WIND DAMAGE IS
MOVING OFF THE COAST. UPSTREAM CONVECTION APPROACHING THE CSRA
LOOKS SUB-SEVERE AND WILL LIKELY REMAIN SO GIVEN THE AMOUNT OF
OVERTURNING THAT HAS OCCURRED OVER THE AREA. SEVERE TSTM WATCH
117 HAS BEEN CLEARED FOR ALL BUT THE GEORGIA COASTAL COUNTIES...
INCLUDING THE ADJACENT MARINE AREA. WILL LIKELY BE ABLE TO CANCEL
THESE AREAS WITHIN THE NEXT HOUR. UPDATED GRIDS/TEXT PRODUCTS HAVE
BEEN ISSUED.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
SHORT TERM IMPACTS WILL BE FROM SEVERE TSTMS APPROACHING FROM THE
WEST. CURRENT TIMING TAKES THE QLCS THROUGH KSAV ROUGHLY 02-04Z
AND KCHS 03-05Z. GUSTY WINDS...HAIL...AND VERY HEAVY RAIN WILL
LIKELY ACCOMPANY THESE STORMS. HIGHEST CONFIDENCE FOR SEVERE
IMPACTS WILL BE AT KSAV. WILL CARRY 2SM TSRA BR TEMPO 1/2SM +TSRA
FG SCT010 BKN025CB TO COVER FOR NOW. AT KCHS...ITS A BIT MORE
UNCERTAIN IF THE TSTMS WILL BE WEAKENING AS THEY APPROACH THE
TERMINAL. WILL CARRY TEMPO 3SM TSRA TEMPO 1SM TSRA FOR NOW.
AMENDMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT. STILL A POTENTIAL FOR LOW CLOUDS TO DEVELOP LATE.
OTHERWISE VFR.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR AMZ374.

&&

$$




000
FXUS62 KCHS 260151
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
951 PM EDT SAT APR 25 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SEVERE QLCS WITH A HISTORY OF PRODUCING WIDESPREAD WIND DAMAGE IS
MOVING OFF THE COAST. UPSTREAM CONVECTION APPROACHING THE CSRA
LOOKS SUB-SEVERE AND WILL LIKELY REMAIN SO GIVEN THE AMOUNT OF
OVERTURNING THAT HAS OCCURRED OVER THE AREA. SEVERE TSTM WATCH
117 HAS BEEN CLEARED FOR ALL BUT THE GEORGIA COASTAL COUNTIES...
INCLUDING THE ADJACENT MARINE AREA. WILL LIKELY BE ABLE TO CANCEL
THESE AREAS WITHIN THE NEXT HOUR. UPDATED GRIDS/TEXT PRODUCTS HAVE
BEEN ISSUED.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
SHORT TERM IMPACTS WILL BE FROM SEVERE TSTMS APPROACHING FROM THE
WEST. CURRENT TIMING TAKES THE QLCS THROUGH KSAV ROUGHLY 02-04Z
AND KCHS 03-05Z. GUSTY WINDS...HAIL...AND VERY HEAVY RAIN WILL
LIKELY ACCOMPANY THESE STORMS. HIGHEST CONFIDENCE FOR SEVERE
IMPACTS WILL BE AT KSAV. WILL CARRY 2SM TSRA BR TEMPO 1/2SM +TSRA
FG SCT010 BKN025CB TO COVER FOR NOW. AT KCHS...ITS A BIT MORE
UNCERTAIN IF THE TSTMS WILL BE WEAKENING AS THEY APPROACH THE
TERMINAL. WILL CARRY TEMPO 3SM TSRA TEMPO 1SM TSRA FOR NOW.
AMENDMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT. STILL A POTENTIAL FOR LOW CLOUDS TO DEVELOP LATE.
OTHERWISE VFR.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR AMZ374.

&&

$$



000
FXUS62 KCHS 260047
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
847 PM EDT SAT APR 25 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MESOSCALE UPDATE...EARLIER DISCREET SUPERCELLS HAVE BEGUN TO
MERGE WITH THE APPROACHING QLCS. KCLX/KVAX RADAR TRENDS SUGGEST
THE QLCS WILL MOST LIKELY REMAIN CONFINED TO COASTAL SOUTHEAST
GEORGIA...POSSIBLY EXTENDING AS FAR NORTH AS BEAUFORT OR EDISTO
BEACH. THE RISK FOR THE CHARLESTON METRO AREA APPEARS TO BE
DIMINISHING WITH TIME. HOWEVER...CELLS CONTINUE TO FIRE OVER THE
CSRA SO THE RISK HAS NOT DIMINISHED ENOUGH TO JUSTIFY DROPPING
THE SEVERE TSTM WATCH ACROSS INLAND AREAS OR THE CHARLESTON TRI-
COUNTY AREA JUST YET. IN ADDITION TO DAMAGING WINDS AND LARGE
HAIL...HEAVY RAIN AND FLOODING COULD POSE A PROBLEM FOR SOME
AREAS...INCLUDING THE SAVANNAH METRO AREA. AN ISOLATED TORNADO IS
ALSO A POSSIBILITY.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
SHORT TERM IMPACTS WILL BE FROM SEVERE TSTMS APPROACHING FROM THE
WEST. CURRENT TIMING TAKES THE QLCS THROUGH KSAV ROUGHLY 02-04Z
AND KCHS 03-05Z. GUSTY WINDS...HAIL...AND VERY HEAVY RAIN WILL
LIKELY ACCOMPANY THESE STORMS. HIGHEST CONFIDENCE FOR SEVERE
IMPACTS WILL BE AT KSAV. WILL CARRY 2SM TSRA BR TEMPO 1/2SM +TSRA
FG SCT010 BKN025CB TO COVER FOR NOW. AT KCHS...ITS A BIT MORE
UNCERTAIN IF THE TSTMS WILL BE WEAKENING AS THEY APPROACH THE
TERMINAL. WILL CARRY TEMPO 3SM TSRA TEMPO 1SM TSRA FOR NOW.
AMENDMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT. STILL A POTENTIAL FOR LOW CLOUDS TO DEVELOP LATE.
OTHERWISE VFR.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR AMZ374.

&&

$$



000
FXUS62 KCHS 260047
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
847 PM EDT SAT APR 25 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MESOSCALE UPDATE...EARLIER DISCREET SUPERCELLS HAVE BEGUN TO
MERGE WITH THE APPROACHING QLCS. KCLX/KVAX RADAR TRENDS SUGGEST
THE QLCS WILL MOST LIKELY REMAIN CONFINED TO COASTAL SOUTHEAST
GEORGIA...POSSIBLY EXTENDING AS FAR NORTH AS BEAUFORT OR EDISTO
BEACH. THE RISK FOR THE CHARLESTON METRO AREA APPEARS TO BE
DIMINISHING WITH TIME. HOWEVER...CELLS CONTINUE TO FIRE OVER THE
CSRA SO THE RISK HAS NOT DIMINISHED ENOUGH TO JUSTIFY DROPPING
THE SEVERE TSTM WATCH ACROSS INLAND AREAS OR THE CHARLESTON TRI-
COUNTY AREA JUST YET. IN ADDITION TO DAMAGING WINDS AND LARGE
HAIL...HEAVY RAIN AND FLOODING COULD POSE A PROBLEM FOR SOME
AREAS...INCLUDING THE SAVANNAH METRO AREA. AN ISOLATED TORNADO IS
ALSO A POSSIBILITY.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
SHORT TERM IMPACTS WILL BE FROM SEVERE TSTMS APPROACHING FROM THE
WEST. CURRENT TIMING TAKES THE QLCS THROUGH KSAV ROUGHLY 02-04Z
AND KCHS 03-05Z. GUSTY WINDS...HAIL...AND VERY HEAVY RAIN WILL
LIKELY ACCOMPANY THESE STORMS. HIGHEST CONFIDENCE FOR SEVERE
IMPACTS WILL BE AT KSAV. WILL CARRY 2SM TSRA BR TEMPO 1/2SM +TSRA
FG SCT010 BKN025CB TO COVER FOR NOW. AT KCHS...ITS A BIT MORE
UNCERTAIN IF THE TSTMS WILL BE WEAKENING AS THEY APPROACH THE
TERMINAL. WILL CARRY TEMPO 3SM TSRA TEMPO 1SM TSRA FOR NOW.
AMENDMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT. STILL A POTENTIAL FOR LOW CLOUDS TO DEVELOP LATE.
OTHERWISE VFR.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR AMZ374.

&&

$$




000
FXUS62 KCHS 260047
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
847 PM EDT SAT APR 25 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MESOSCALE UPDATE...EARLIER DISCREET SUPERCELLS HAVE BEGUN TO
MERGE WITH THE APPROACHING QLCS. KCLX/KVAX RADAR TRENDS SUGGEST
THE QLCS WILL MOST LIKELY REMAIN CONFINED TO COASTAL SOUTHEAST
GEORGIA...POSSIBLY EXTENDING AS FAR NORTH AS BEAUFORT OR EDISTO
BEACH. THE RISK FOR THE CHARLESTON METRO AREA APPEARS TO BE
DIMINISHING WITH TIME. HOWEVER...CELLS CONTINUE TO FIRE OVER THE
CSRA SO THE RISK HAS NOT DIMINISHED ENOUGH TO JUSTIFY DROPPING
THE SEVERE TSTM WATCH ACROSS INLAND AREAS OR THE CHARLESTON TRI-
COUNTY AREA JUST YET. IN ADDITION TO DAMAGING WINDS AND LARGE
HAIL...HEAVY RAIN AND FLOODING COULD POSE A PROBLEM FOR SOME
AREAS...INCLUDING THE SAVANNAH METRO AREA. AN ISOLATED TORNADO IS
ALSO A POSSIBILITY.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
SHORT TERM IMPACTS WILL BE FROM SEVERE TSTMS APPROACHING FROM THE
WEST. CURRENT TIMING TAKES THE QLCS THROUGH KSAV ROUGHLY 02-04Z
AND KCHS 03-05Z. GUSTY WINDS...HAIL...AND VERY HEAVY RAIN WILL
LIKELY ACCOMPANY THESE STORMS. HIGHEST CONFIDENCE FOR SEVERE
IMPACTS WILL BE AT KSAV. WILL CARRY 2SM TSRA BR TEMPO 1/2SM +TSRA
FG SCT010 BKN025CB TO COVER FOR NOW. AT KCHS...ITS A BIT MORE
UNCERTAIN IF THE TSTMS WILL BE WEAKENING AS THEY APPROACH THE
TERMINAL. WILL CARRY TEMPO 3SM TSRA TEMPO 1SM TSRA FOR NOW.
AMENDMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT. STILL A POTENTIAL FOR LOW CLOUDS TO DEVELOP LATE.
OTHERWISE VFR.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR AMZ374.

&&

$$



000
FXUS62 KCAE 260011
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
811 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 00Z SHOWS
SHOWERS AND ISOLATED STORMS ENTERING THE SOUTHERN PART OF THE CWA
ALTHOUGH A MAJORITY OF THE ACTIVITY REMAINS SOUTH OF THE FA.
CANNOT RULE OUT SEEING SOME OF THIS ACTIVITY ACROSS THE CENTRAL
MIDLANDS AS THE EVENING PROGRESSES BUT WITH LACK OF DAYTIME
HEATING...EXPECT SEVERE THREAT TO REMAIN LOW IN THE CENTRAL
MIDLANDS. SHEAR VALUES REMAIN HIGH THROUGH THE EVENING...WHICH
WOULD HELP SUPPORT ROTATING STORMS IF ANY CAN PUSH INTO THE AREA.
THE MAIN THREAT APPEARS TO BE DAMAGING WIND AND HAIL WHICH HAS
BEEN REPORTED WITH SOME OF THE STORMS IN CENTRAL GEORGIA. SPC HAS
TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN AND
EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST. A
SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT THROUGH MIDNIGHT FOR
BURKE...BARNWELL...BAMBERG AND ORANGEBURG COUNTIES.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
REGIONAL RADAR LOOP AS OF 00Z BRINGING SHOWERS AND STORMS INTO THE
SOUTHERN PART OF THE FORECAST AREA. CANNOT RULE OUT STORMS
REACHING THE AGS/DNL/OGB TERMINALS BETWEEN 01Z AND 03Z SO HAVE
ADDED A TEMPO GROUP WITH ASSOCIATED RESTRICTIONS. CEILINGS HAVE
RETURNED TO VFR AT ALL OF THE TERMINALS FOR NOW. MODELS INDICATE POTENTIAL
FOR RESTRICTIONS RETURNING AFTER 06Z. HAVE ADDED MVFR RESTRICTIONS
AT AGS/DNL/OGB TOWARD DAYBREAK ALTHOUGH CONFIDENCE IS LOW AT THIS
TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN THE TERMINAL
FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF THE SHEAR.
THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY BUT WITH
SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED TOO LOW
TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS LAMP AND THE
NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND GUSTS NEAR 24
KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KCAE 260011
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
811 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 00Z SHOWS
SHOWERS AND ISOLATED STORMS ENTERING THE SOUTHERN PART OF THE CWA
ALTHOUGH A MAJORITY OF THE ACTIVITY REMAINS SOUTH OF THE FA.
CANNOT RULE OUT SEEING SOME OF THIS ACTIVITY ACROSS THE CENTRAL
MIDLANDS AS THE EVENING PROGRESSES BUT WITH LACK OF DAYTIME
HEATING...EXPECT SEVERE THREAT TO REMAIN LOW IN THE CENTRAL
MIDLANDS. SHEAR VALUES REMAIN HIGH THROUGH THE EVENING...WHICH
WOULD HELP SUPPORT ROTATING STORMS IF ANY CAN PUSH INTO THE AREA.
THE MAIN THREAT APPEARS TO BE DAMAGING WIND AND HAIL WHICH HAS
BEEN REPORTED WITH SOME OF THE STORMS IN CENTRAL GEORGIA. SPC HAS
TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN AND
EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST. A
SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT THROUGH MIDNIGHT FOR
BURKE...BARNWELL...BAMBERG AND ORANGEBURG COUNTIES.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
REGIONAL RADAR LOOP AS OF 00Z BRINGING SHOWERS AND STORMS INTO THE
SOUTHERN PART OF THE FORECAST AREA. CANNOT RULE OUT STORMS
REACHING THE AGS/DNL/OGB TERMINALS BETWEEN 01Z AND 03Z SO HAVE
ADDED A TEMPO GROUP WITH ASSOCIATED RESTRICTIONS. CEILINGS HAVE
RETURNED TO VFR AT ALL OF THE TERMINALS FOR NOW. MODELS INDICATE POTENTIAL
FOR RESTRICTIONS RETURNING AFTER 06Z. HAVE ADDED MVFR RESTRICTIONS
AT AGS/DNL/OGB TOWARD DAYBREAK ALTHOUGH CONFIDENCE IS LOW AT THIS
TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN THE TERMINAL
FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF THE SHEAR.
THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY BUT WITH
SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED TOO LOW
TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS LAMP AND THE
NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND GUSTS NEAR 24
KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCAE 260011
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
811 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 00Z SHOWS
SHOWERS AND ISOLATED STORMS ENTERING THE SOUTHERN PART OF THE CWA
ALTHOUGH A MAJORITY OF THE ACTIVITY REMAINS SOUTH OF THE FA.
CANNOT RULE OUT SEEING SOME OF THIS ACTIVITY ACROSS THE CENTRAL
MIDLANDS AS THE EVENING PROGRESSES BUT WITH LACK OF DAYTIME
HEATING...EXPECT SEVERE THREAT TO REMAIN LOW IN THE CENTRAL
MIDLANDS. SHEAR VALUES REMAIN HIGH THROUGH THE EVENING...WHICH
WOULD HELP SUPPORT ROTATING STORMS IF ANY CAN PUSH INTO THE AREA.
THE MAIN THREAT APPEARS TO BE DAMAGING WIND AND HAIL WHICH HAS
BEEN REPORTED WITH SOME OF THE STORMS IN CENTRAL GEORGIA. SPC HAS
TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN AND
EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST. A
SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT THROUGH MIDNIGHT FOR
BURKE...BARNWELL...BAMBERG AND ORANGEBURG COUNTIES.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
REGIONAL RADAR LOOP AS OF 00Z BRINGING SHOWERS AND STORMS INTO THE
SOUTHERN PART OF THE FORECAST AREA. CANNOT RULE OUT STORMS
REACHING THE AGS/DNL/OGB TERMINALS BETWEEN 01Z AND 03Z SO HAVE
ADDED A TEMPO GROUP WITH ASSOCIATED RESTRICTIONS. CEILINGS HAVE
RETURNED TO VFR AT ALL OF THE TERMINALS FOR NOW. MODELS INDICATE POTENTIAL
FOR RESTRICTIONS RETURNING AFTER 06Z. HAVE ADDED MVFR RESTRICTIONS
AT AGS/DNL/OGB TOWARD DAYBREAK ALTHOUGH CONFIDENCE IS LOW AT THIS
TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN THE TERMINAL
FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF THE SHEAR.
THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY BUT WITH
SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED TOO LOW
TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS LAMP AND THE
NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND GUSTS NEAR 24
KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KCAE 260011
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
811 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 00Z SHOWS
SHOWERS AND ISOLATED STORMS ENTERING THE SOUTHERN PART OF THE CWA
ALTHOUGH A MAJORITY OF THE ACTIVITY REMAINS SOUTH OF THE FA.
CANNOT RULE OUT SEEING SOME OF THIS ACTIVITY ACROSS THE CENTRAL
MIDLANDS AS THE EVENING PROGRESSES BUT WITH LACK OF DAYTIME
HEATING...EXPECT SEVERE THREAT TO REMAIN LOW IN THE CENTRAL
MIDLANDS. SHEAR VALUES REMAIN HIGH THROUGH THE EVENING...WHICH
WOULD HELP SUPPORT ROTATING STORMS IF ANY CAN PUSH INTO THE AREA.
THE MAIN THREAT APPEARS TO BE DAMAGING WIND AND HAIL WHICH HAS
BEEN REPORTED WITH SOME OF THE STORMS IN CENTRAL GEORGIA. SPC HAS
TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN AND
EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST. A
SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT THROUGH MIDNIGHT FOR
BURKE...BARNWELL...BAMBERG AND ORANGEBURG COUNTIES.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
REGIONAL RADAR LOOP AS OF 00Z BRINGING SHOWERS AND STORMS INTO THE
SOUTHERN PART OF THE FORECAST AREA. CANNOT RULE OUT STORMS
REACHING THE AGS/DNL/OGB TERMINALS BETWEEN 01Z AND 03Z SO HAVE
ADDED A TEMPO GROUP WITH ASSOCIATED RESTRICTIONS. CEILINGS HAVE
RETURNED TO VFR AT ALL OF THE TERMINALS FOR NOW. MODELS INDICATE POTENTIAL
FOR RESTRICTIONS RETURNING AFTER 06Z. HAVE ADDED MVFR RESTRICTIONS
AT AGS/DNL/OGB TOWARD DAYBREAK ALTHOUGH CONFIDENCE IS LOW AT THIS
TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN THE TERMINAL
FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF THE SHEAR.
THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY BUT WITH
SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED TOO LOW
TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS LAMP AND THE
NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND GUSTS NEAR 24
KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KGSP 260004
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
804 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AT KCLT...INITIALIZED TAF MVFR AS CURRENT IFR RESTRICTIONS SHOULD
IMPROVE SHORTLY.  ADDED TSRA TEMPO FROM 07Z-10Z TO ACCOUNT FOR
UPSTREAM MCS PROPAGATION/SURVIVAL THROUGH THE MOUNTAINS AS SHOWN ON
THE LATEST HRRR.  HOWEVER...IF THIS TRACK DOES PAN OUT...LITTLE TO
NO INSTABILITY WILL BE AVAILABLE FOR CONVECTION THUS ANY STRONG TSRA
IS LIKELY RULED OUT.  ACTUALLY WOULDNT BE SURPRISED IF ITS NOTHING
MORE THAN A FEW SHOWERS.  OTHERWISE...GUIDANCE CONTINUES TO FAVOR
PATCHY DENSE FOG AROUND THE LOWER NC PIEDMONT BY MORNING THUS ADDED
FM GROUP TO INDICATE IFR RESTRICTIONS.  IMPROVED TAF TO LOW VFR
AROUND 15Z WITH NORTHERLY WINDS PREVAILING AHEAD OF A PROB30 IN THE
AFTN FOR POSSIBLE CONVECTION ALONG SLOW MOVING FRONTAL AXIS.

ELSEWHERE...MODELS STILL FAVOR PROLONGED LIFR/IFR RESTRICTIONS AT
KHKY THUS TAF REFLECTS SUCH.  OTHERWISE...ALL TAFS INITIALIZE VFR
THROUGH THE EARLY EVENING HOURS.  MCS SLIDING THROUGH CENTRAL KY AT
THIS TIME IS PROGGED TO ADVANCE THROUGH THE PLATEAU INTO THE HIGH
TERRAIN OF WESTERN NC AFTER MIDNIGHT.  SOME CAM SOLUTIONS INDICATE
SURVIVAL OF SAID MCS THROUGH THE MOUNTAINS.  THUS...TAFS FEATURE
VCTS MENTION TO ACCOUNT FOR ANY ENHANCED CONVECTION.  AS WITH KCLT
ABOVE...EXPECTING INSTABILITY TO BE AT A PREMIUM...ESPECIALLY EAST
OF THE MTNS THEREFORE NO ROBUST CONVECTION IS EXPECTED.  WITH THAT
LOWERED ALL SITES TO EITHER LOW VFR OR MVFR AMIDST LIGHT/MODERATE
NORTHERLY WINDS.  DID INCLUDE EARLY MORNING PATCHY FOG AT ALL SITES
WITH SOME ISOLATED DENSE FOG EXPECTED OVER THE NC PIEDMONT...THUS DO
CARRY 1/2SM AT KHKY.  OTHERWISE CONDITIONS WILL IMPROVE THROUGH
MORNING WITH SHRA/TSRA EXITING THE REGION...IF PRESENT.  DID
REINTRODUCE WX MENTION LATE IN THE PERIOD TO ACCOUNT FOR SLOW MOVING
FRONTAL AXIS ON SUNDAY AFTERNOON/EVENING.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON SUNDAY THEN
FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW PRESSURE
SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND THURSDAY.

CONFIDENCE TABLE...

            00-06Z        06-12Z        12-18Z        18-00Z
KCLT       HIGH  91%     MED   71%     HIGH  81%     HIGH  80%
KGSP       MED   74%     MED   70%     HIGH  96%     HIGH  86%
KAVL       HIGH 100%     HIGH 100%     HIGH  95%     HIGH  90%
KHKY       MED   72%     MED   77%     LOW   57%     HIGH  85%
KGMU       HIGH  83%     HIGH  82%     HIGH  93%     HIGH  96%
KAND       HIGH  86%     HIGH  87%     HIGH  91%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...CDG/JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...CDG



000
FXUS62 KGSP 260004
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
804 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AT KCLT...INITIALIZED TAF MVFR AS CURRENT IFR RESTRICTIONS SHOULD
IMPROVE SHORTLY.  ADDED TSRA TEMPO FROM 07Z-10Z TO ACCOUNT FOR
UPSTREAM MCS PROPAGATION/SURVIVAL THROUGH THE MOUNTAINS AS SHOWN ON
THE LATEST HRRR.  HOWEVER...IF THIS TRACK DOES PAN OUT...LITTLE TO
NO INSTABILITY WILL BE AVAILABLE FOR CONVECTION THUS ANY STRONG TSRA
IS LIKELY RULED OUT.  ACTUALLY WOULDNT BE SURPRISED IF ITS NOTHING
MORE THAN A FEW SHOWERS.  OTHERWISE...GUIDANCE CONTINUES TO FAVOR
PATCHY DENSE FOG AROUND THE LOWER NC PIEDMONT BY MORNING THUS ADDED
FM GROUP TO INDICATE IFR RESTRICTIONS.  IMPROVED TAF TO LOW VFR
AROUND 15Z WITH NORTHERLY WINDS PREVAILING AHEAD OF A PROB30 IN THE
AFTN FOR POSSIBLE CONVECTION ALONG SLOW MOVING FRONTAL AXIS.

ELSEWHERE...MODELS STILL FAVOR PROLONGED LIFR/IFR RESTRICTIONS AT
KHKY THUS TAF REFLECTS SUCH.  OTHERWISE...ALL TAFS INITIALIZE VFR
THROUGH THE EARLY EVENING HOURS.  MCS SLIDING THROUGH CENTRAL KY AT
THIS TIME IS PROGGED TO ADVANCE THROUGH THE PLATEAU INTO THE HIGH
TERRAIN OF WESTERN NC AFTER MIDNIGHT.  SOME CAM SOLUTIONS INDICATE
SURVIVAL OF SAID MCS THROUGH THE MOUNTAINS.  THUS...TAFS FEATURE
VCTS MENTION TO ACCOUNT FOR ANY ENHANCED CONVECTION.  AS WITH KCLT
ABOVE...EXPECTING INSTABILITY TO BE AT A PREMIUM...ESPECIALLY EAST
OF THE MTNS THEREFORE NO ROBUST CONVECTION IS EXPECTED.  WITH THAT
LOWERED ALL SITES TO EITHER LOW VFR OR MVFR AMIDST LIGHT/MODERATE
NORTHERLY WINDS.  DID INCLUDE EARLY MORNING PATCHY FOG AT ALL SITES
WITH SOME ISOLATED DENSE FOG EXPECTED OVER THE NC PIEDMONT...THUS DO
CARRY 1/2SM AT KHKY.  OTHERWISE CONDITIONS WILL IMPROVE THROUGH
MORNING WITH SHRA/TSRA EXITING THE REGION...IF PRESENT.  DID
REINTRODUCE WX MENTION LATE IN THE PERIOD TO ACCOUNT FOR SLOW MOVING
FRONTAL AXIS ON SUNDAY AFTERNOON/EVENING.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON SUNDAY THEN
FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW PRESSURE
SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND THURSDAY.

CONFIDENCE TABLE...

            00-06Z        06-12Z        12-18Z        18-00Z
KCLT       HIGH  91%     MED   71%     HIGH  81%     HIGH  80%
KGSP       MED   74%     MED   70%     HIGH  96%     HIGH  86%
KAVL       HIGH 100%     HIGH 100%     HIGH  95%     HIGH  90%
KHKY       MED   72%     MED   77%     LOW   57%     HIGH  85%
KGMU       HIGH  83%     HIGH  82%     HIGH  93%     HIGH  96%
KAND       HIGH  86%     HIGH  87%     HIGH  91%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...CDG/JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...CDG




000
FXUS62 KGSP 260004
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
804 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AT KCLT...INITIALIZED TAF MVFR AS CURRENT IFR RESTRICTIONS SHOULD
IMPROVE SHORTLY.  ADDED TSRA TEMPO FROM 07Z-10Z TO ACCOUNT FOR
UPSTREAM MCS PROPAGATION/SURVIVAL THROUGH THE MOUNTAINS AS SHOWN ON
THE LATEST HRRR.  HOWEVER...IF THIS TRACK DOES PAN OUT...LITTLE TO
NO INSTABILITY WILL BE AVAILABLE FOR CONVECTION THUS ANY STRONG TSRA
IS LIKELY RULED OUT.  ACTUALLY WOULDNT BE SURPRISED IF ITS NOTHING
MORE THAN A FEW SHOWERS.  OTHERWISE...GUIDANCE CONTINUES TO FAVOR
PATCHY DENSE FOG AROUND THE LOWER NC PIEDMONT BY MORNING THUS ADDED
FM GROUP TO INDICATE IFR RESTRICTIONS.  IMPROVED TAF TO LOW VFR
AROUND 15Z WITH NORTHERLY WINDS PREVAILING AHEAD OF A PROB30 IN THE
AFTN FOR POSSIBLE CONVECTION ALONG SLOW MOVING FRONTAL AXIS.

ELSEWHERE...MODELS STILL FAVOR PROLONGED LIFR/IFR RESTRICTIONS AT
KHKY THUS TAF REFLECTS SUCH.  OTHERWISE...ALL TAFS INITIALIZE VFR
THROUGH THE EARLY EVENING HOURS.  MCS SLIDING THROUGH CENTRAL KY AT
THIS TIME IS PROGGED TO ADVANCE THROUGH THE PLATEAU INTO THE HIGH
TERRAIN OF WESTERN NC AFTER MIDNIGHT.  SOME CAM SOLUTIONS INDICATE
SURVIVAL OF SAID MCS THROUGH THE MOUNTAINS.  THUS...TAFS FEATURE
VCTS MENTION TO ACCOUNT FOR ANY ENHANCED CONVECTION.  AS WITH KCLT
ABOVE...EXPECTING INSTABILITY TO BE AT A PREMIUM...ESPECIALLY EAST
OF THE MTNS THEREFORE NO ROBUST CONVECTION IS EXPECTED.  WITH THAT
LOWERED ALL SITES TO EITHER LOW VFR OR MVFR AMIDST LIGHT/MODERATE
NORTHERLY WINDS.  DID INCLUDE EARLY MORNING PATCHY FOG AT ALL SITES
WITH SOME ISOLATED DENSE FOG EXPECTED OVER THE NC PIEDMONT...THUS DO
CARRY 1/2SM AT KHKY.  OTHERWISE CONDITIONS WILL IMPROVE THROUGH
MORNING WITH SHRA/TSRA EXITING THE REGION...IF PRESENT.  DID
REINTRODUCE WX MENTION LATE IN THE PERIOD TO ACCOUNT FOR SLOW MOVING
FRONTAL AXIS ON SUNDAY AFTERNOON/EVENING.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON SUNDAY THEN
FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW PRESSURE
SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND THURSDAY.

CONFIDENCE TABLE...

            00-06Z        06-12Z        12-18Z        18-00Z
KCLT       HIGH  91%     MED   71%     HIGH  81%     HIGH  80%
KGSP       MED   74%     MED   70%     HIGH  96%     HIGH  86%
KAVL       HIGH 100%     HIGH 100%     HIGH  95%     HIGH  90%
KHKY       MED   72%     MED   77%     LOW   57%     HIGH  85%
KGMU       HIGH  83%     HIGH  82%     HIGH  93%     HIGH  96%
KAND       HIGH  86%     HIGH  87%     HIGH  91%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...CDG/JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...CDG



000
FXUS62 KGSP 260004
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
804 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 755 PM EDT SATURDAY...WEDGE STARTING TO BACK AWAY LEADING TO
SCT SKIES AND DRIER WX.  THUS MADE SLIGHT TWEAKS TO POPS/TEMPS/DEWS
IN THE EXTREME NEAR TERM TO REFLECT MOST RECENT OBSERVATIONS...AND
GUIDANCE.  LATEST HRRR/RAP STILL SHOW A SUSTAINED MCS SLIDING INTO
THE NC HIGH TERRAIN AROUND THE 2-3AM TIMEFRAME...WITH THE HRRR
SHOWING SOME SURVIVAL OF THIS CONVECTION ACROSS THE NC PIEDMONT.
THAT SAID...LITTLE NO INSTABILITY WILL BE PRESENT OUT
AHEAD...ESPECIALLY AT THE SFC.  THUS THINKING ANY CONVECTION THAT
DOES SURVIVE WILL WEAKEN SUBSTANTIALLY.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AT KCLT...INITIALIZED TAF MVFR AS CURRENT IFR RESTRICTIONS SHOULD
IMPROVE SHORTLY.  ADDED TSRA TEMPO FROM 07Z-10Z TO ACCOUNT FOR
UPSTREAM MCS PROPAGATION/SURVIVAL THROUGH THE MOUNTAINS AS SHOWN ON
THE LATEST HRRR.  HOWEVER...IF THIS TRACK DOES PAN OUT...LITTLE TO
NO INSTABILITY WILL BE AVAILABLE FOR CONVECTION THUS ANY STRONG TSRA
IS LIKELY RULED OUT.  ACTUALLY WOULDNT BE SURPRISED IF ITS NOTHING
MORE THAN A FEW SHOWERS.  OTHERWISE...GUIDANCE CONTINUES TO FAVOR
PATCHY DENSE FOG AROUND THE LOWER NC PIEDMONT BY MORNING THUS ADDED
FM GROUP TO INDICATE IFR RESTRICTIONS.  IMPROVED TAF TO LOW VFR
AROUND 15Z WITH NORTHERLY WINDS PREVAILING AHEAD OF A PROB30 IN THE
AFTN FOR POSSIBLE CONVECTION ALONG SLOW MOVING FRONTAL AXIS.

ELSEWHERE...MODELS STILL FAVOR PROLONGED LIFR/IFR RESTRICTIONS AT
KHKY THUS TAF REFLECTS SUCH.  OTHERWISE...ALL TAFS INITIALIZE VFR
THROUGH THE EARLY EVENING HOURS.  MCS SLIDING THROUGH CENTRAL KY AT
THIS TIME IS PROGGED TO ADVANCE THROUGH THE PLATEAU INTO THE HIGH
TERRAIN OF WESTERN NC AFTER MIDNIGHT.  SOME CAM SOLUTIONS INDICATE
SURVIVAL OF SAID MCS THROUGH THE MOUNTAINS.  THUS...TAFS FEATURE
VCTS MENTION TO ACCOUNT FOR ANY ENHANCED CONVECTION.  AS WITH KCLT
ABOVE...EXPECTING INSTABILITY TO BE AT A PREMIUM...ESPECIALLY EAST
OF THE MTNS THEREFORE NO ROBUST CONVECTION IS EXPECTED.  WITH THAT
LOWERED ALL SITES TO EITHER LOW VFR OR MVFR AMIDST LIGHT/MODERATE
NORTHERLY WINDS.  DID INCLUDE EARLY MORNING PATCHY FOG AT ALL SITES
WITH SOME ISOLATED DENSE FOG EXPECTED OVER THE NC PIEDMONT...THUS DO
CARRY 1/2SM AT KHKY.  OTHERWISE CONDITIONS WILL IMPROVE THROUGH
MORNING WITH SHRA/TSRA EXITING THE REGION...IF PRESENT.  DID
REINTRODUCE WX MENTION LATE IN THE PERIOD TO ACCOUNT FOR SLOW MOVING
FRONTAL AXIS ON SUNDAY AFTERNOON/EVENING.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION ON SUNDAY THEN
FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW PRESSURE
SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND THURSDAY.

CONFIDENCE TABLE...

            00-06Z        06-12Z        12-18Z        18-00Z
KCLT       HIGH  91%     MED   71%     HIGH  81%     HIGH  80%
KGSP       MED   74%     MED   70%     HIGH  96%     HIGH  86%
KAVL       HIGH 100%     HIGH 100%     HIGH  95%     HIGH  90%
KHKY       MED   72%     MED   77%     LOW   57%     HIGH  85%
KGMU       HIGH  83%     HIGH  82%     HIGH  93%     HIGH  96%
KAND       HIGH  86%     HIGH  87%     HIGH  91%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...CDG/JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...CDG




000
FXUS62 KCHS 252348
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
748 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS MOVING INTO THE AREA...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MESOSCALE UPDATE...A LARGE SUPERCELL WITH A HISTORY OF PRODUCING
BASEBALL SIZE HAIL IS MOVING INTO CANDLER COUNTY ATTM. THE
ENVIRONMENT AHEAD OF THE STORM CONTINUES TO FAVOR VERY LARGE HAIL
AND DESTRUCTIVE WINDS. FARTHER TO THE SOUTHWEST...A QLCS IS
RAPIDLY MATURING OVER SOUTH-CENTRAL GEORGIA. THE QLCS IS ON TRACK
TO CROSS MUCH OF SOUTHEAST GEORGIA AND POSSIBLY SOUTHEAST SOUTH
CAROLINA AS FAR NORTH AS EDISTO BEACH. INSTABILITY REMAINS MODEST
AHEAD OF THE CONVECTIVE CLUSTER AND SUFFICIENT TO MAINTAIN STRONG
UPDRAFTS FOR SEVERAL MORE HOURS. 0-6KM BULK SHEAR REMAINS
SUPPORTIVE OF SUPERCELLS.

THERE IS A POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. GRIDS/TEXT PRODUCTS HAVE BEEN UPDATED TO
REFLECT CURRENT SHORT TERM TRENDS.


&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM IMPACTS WILL BE FROM SEVERE TSTMS APPROACHING FROM THE
WEST. CURRENT TIMING TAKES THE QLCS THROUGH KSAV ROUGHLY 02-04Z
AND KCHS 03-05Z. GUSTY WINDS...HAIL...AND VERY HEAVY RAIN WILL
LIKELY ACCOMPANY THESE STORMS. HIGHEST CONFIDENCE FOR SEVERE
IMPACTS WILL BE AT KSAV. WILL CARRY 2SM TSRA BR TEMPO 1/2SM +TSRA
FG SCT010 BKN025CB TO COVER FOR NOW. AT KCHS...ITS A BIT MORE
UNCERTAIN IF THE TSTMS WILL BE WEAKENING AS THEY APPROACH THE
TERMINAL. WILL CARRY TEMPO 3SM TSRA TEMPO 1SM TSRA FOR NOW.
AMENDMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT. STILL A POTENTIAL FOR LOW CLOUDS TO DEVELOP LATE.
OTHERWISE VFR.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KCHS 252348
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
748 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS MOVING INTO THE AREA...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MESOSCALE UPDATE...A LARGE SUPERCELL WITH A HISTORY OF PRODUCING
BASEBALL SIZE HAIL IS MOVING INTO CANDLER COUNTY ATTM. THE
ENVIRONMENT AHEAD OF THE STORM CONTINUES TO FAVOR VERY LARGE HAIL
AND DESTRUCTIVE WINDS. FARTHER TO THE SOUTHWEST...A QLCS IS
RAPIDLY MATURING OVER SOUTH-CENTRAL GEORGIA. THE QLCS IS ON TRACK
TO CROSS MUCH OF SOUTHEAST GEORGIA AND POSSIBLY SOUTHEAST SOUTH
CAROLINA AS FAR NORTH AS EDISTO BEACH. INSTABILITY REMAINS MODEST
AHEAD OF THE CONVECTIVE CLUSTER AND SUFFICIENT TO MAINTAIN STRONG
UPDRAFTS FOR SEVERAL MORE HOURS. 0-6KM BULK SHEAR REMAINS
SUPPORTIVE OF SUPERCELLS.

THERE IS A POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. GRIDS/TEXT PRODUCTS HAVE BEEN UPDATED TO
REFLECT CURRENT SHORT TERM TRENDS.


&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM IMPACTS WILL BE FROM SEVERE TSTMS APPROACHING FROM THE
WEST. CURRENT TIMING TAKES THE QLCS THROUGH KSAV ROUGHLY 02-04Z
AND KCHS 03-05Z. GUSTY WINDS...HAIL...AND VERY HEAVY RAIN WILL
LIKELY ACCOMPANY THESE STORMS. HIGHEST CONFIDENCE FOR SEVERE
IMPACTS WILL BE AT KSAV. WILL CARRY 2SM TSRA BR TEMPO 1/2SM +TSRA
FG SCT010 BKN025CB TO COVER FOR NOW. AT KCHS...ITS A BIT MORE
UNCERTAIN IF THE TSTMS WILL BE WEAKENING AS THEY APPROACH THE
TERMINAL. WILL CARRY TEMPO 3SM TSRA TEMPO 1SM TSRA FOR NOW.
AMENDMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT. STILL A POTENTIAL FOR LOW CLOUDS TO DEVELOP LATE.
OTHERWISE VFR.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KCHS 252348
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
748 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS MOVING INTO THE AREA...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MESOSCALE UPDATE...A LARGE SUPERCELL WITH A HISTORY OF PRODUCING
BASEBALL SIZE HAIL IS MOVING INTO CANDLER COUNTY ATTM. THE
ENVIRONMENT AHEAD OF THE STORM CONTINUES TO FAVOR VERY LARGE HAIL
AND DESTRUCTIVE WINDS. FARTHER TO THE SOUTHWEST...A QLCS IS
RAPIDLY MATURING OVER SOUTH-CENTRAL GEORGIA. THE QLCS IS ON TRACK
TO CROSS MUCH OF SOUTHEAST GEORGIA AND POSSIBLY SOUTHEAST SOUTH
CAROLINA AS FAR NORTH AS EDISTO BEACH. INSTABILITY REMAINS MODEST
AHEAD OF THE CONVECTIVE CLUSTER AND SUFFICIENT TO MAINTAIN STRONG
UPDRAFTS FOR SEVERAL MORE HOURS. 0-6KM BULK SHEAR REMAINS
SUPPORTIVE OF SUPERCELLS.

THERE IS A POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. GRIDS/TEXT PRODUCTS HAVE BEEN UPDATED TO
REFLECT CURRENT SHORT TERM TRENDS.


&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM IMPACTS WILL BE FROM SEVERE TSTMS APPROACHING FROM THE
WEST. CURRENT TIMING TAKES THE QLCS THROUGH KSAV ROUGHLY 02-04Z
AND KCHS 03-05Z. GUSTY WINDS...HAIL...AND VERY HEAVY RAIN WILL
LIKELY ACCOMPANY THESE STORMS. HIGHEST CONFIDENCE FOR SEVERE
IMPACTS WILL BE AT KSAV. WILL CARRY 2SM TSRA BR TEMPO 1/2SM +TSRA
FG SCT010 BKN025CB TO COVER FOR NOW. AT KCHS...ITS A BIT MORE
UNCERTAIN IF THE TSTMS WILL BE WEAKENING AS THEY APPROACH THE
TERMINAL. WILL CARRY TEMPO 3SM TSRA TEMPO 1SM TSRA FOR NOW.
AMENDMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT. STILL A POTENTIAL FOR LOW CLOUDS TO DEVELOP LATE.
OTHERWISE VFR.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KCHS 252348
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
748 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS MOVING INTO THE AREA...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MESOSCALE UPDATE...A LARGE SUPERCELL WITH A HISTORY OF PRODUCING
BASEBALL SIZE HAIL IS MOVING INTO CANDLER COUNTY ATTM. THE
ENVIRONMENT AHEAD OF THE STORM CONTINUES TO FAVOR VERY LARGE HAIL
AND DESTRUCTIVE WINDS. FARTHER TO THE SOUTHWEST...A QLCS IS
RAPIDLY MATURING OVER SOUTH-CENTRAL GEORGIA. THE QLCS IS ON TRACK
TO CROSS MUCH OF SOUTHEAST GEORGIA AND POSSIBLY SOUTHEAST SOUTH
CAROLINA AS FAR NORTH AS EDISTO BEACH. INSTABILITY REMAINS MODEST
AHEAD OF THE CONVECTIVE CLUSTER AND SUFFICIENT TO MAINTAIN STRONG
UPDRAFTS FOR SEVERAL MORE HOURS. 0-6KM BULK SHEAR REMAINS
SUPPORTIVE OF SUPERCELLS.

THERE IS A POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. GRIDS/TEXT PRODUCTS HAVE BEEN UPDATED TO
REFLECT CURRENT SHORT TERM TRENDS.


&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM IMPACTS WILL BE FROM SEVERE TSTMS APPROACHING FROM THE
WEST. CURRENT TIMING TAKES THE QLCS THROUGH KSAV ROUGHLY 02-04Z
AND KCHS 03-05Z. GUSTY WINDS...HAIL...AND VERY HEAVY RAIN WILL
LIKELY ACCOMPANY THESE STORMS. HIGHEST CONFIDENCE FOR SEVERE
IMPACTS WILL BE AT KSAV. WILL CARRY 2SM TSRA BR TEMPO 1/2SM +TSRA
FG SCT010 BKN025CB TO COVER FOR NOW. AT KCHS...ITS A BIT MORE
UNCERTAIN IF THE TSTMS WILL BE WEAKENING AS THEY APPROACH THE
TERMINAL. WILL CARRY TEMPO 3SM TSRA TEMPO 1SM TSRA FOR NOW.
AMENDMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT. STILL A POTENTIAL FOR LOW CLOUDS TO DEVELOP LATE.
OTHERWISE VFR.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KCHS 252306
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
706 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS LIKELY THIS EVENING...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SEVERE THUNDERSTORM WATCH 117 HAS BEEN ISSUED FOR ALL OF SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA UNTIL MIDNIGHT. GRIDS/TEXT
PRODUCTS HAVE BEEN UPDATED TO REFLECT THE WATCH AND SHORT TERM
TERM TRENDS. PRIMARY HAZARDS WILL BE LARGE HAIL...DAMAGING WINDS
AND FREQUENT CLOUD TO GROUND LIGHTNING ALONG WITH AN ISOLATED
TORNADO. INITIAL MODE WILL BE SUPERCELLS MOVING INTO THE WESTERN
ZONES FOLLOWED BY A QLCS MOVING ACROSS MUCH OF THE FORECAST AREA.

THERE IS POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. UPDATES WILL BE ISSUED AS NEEDED.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
SHORT TERM IMPACTS WILL BE FROM SEVERE TSTMS APPROACHING FROM THE
WEST. CURRENT TIMING TAKES THE QLCS THROUGH KSAV ROUGHLY 02-04Z
AND KCHS 03-05Z. GUSTY WINDS...HAIL...AND VERY HEAVY RAIN WILL
LIKELY ACCOMPANY THESE STORMS. HIGHEST CONFIDENCE FOR SEVERE
IMPACTS WILL BE AT KSAV. WILL CARRY 2SM TSRA BR TEMPO 1/2SM +TSRA
FG SCT010 BKN025CB TO COVER FOR NOW. AT KCHS...ITS A BIT MORE
UNCERTAIN IF THE TSTMS WILL BE WEAKENING AS THEY APPROACH THE
TERMINAL. WILL CARRY TEMPO 3SM TSRA TEMPO 1SM TSRA FOR NOW.
AMENDMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT. STILL A POTENTIAL FOR LOW CLOUDS TO DEVELOP LATE.
OTHERWISE VFR.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KCHS 252306
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
706 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS LIKELY THIS EVENING...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SEVERE THUNDERSTORM WATCH 117 HAS BEEN ISSUED FOR ALL OF SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA UNTIL MIDNIGHT. GRIDS/TEXT
PRODUCTS HAVE BEEN UPDATED TO REFLECT THE WATCH AND SHORT TERM
TERM TRENDS. PRIMARY HAZARDS WILL BE LARGE HAIL...DAMAGING WINDS
AND FREQUENT CLOUD TO GROUND LIGHTNING ALONG WITH AN ISOLATED
TORNADO. INITIAL MODE WILL BE SUPERCELLS MOVING INTO THE WESTERN
ZONES FOLLOWED BY A QLCS MOVING ACROSS MUCH OF THE FORECAST AREA.

THERE IS POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. UPDATES WILL BE ISSUED AS NEEDED.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
SHORT TERM IMPACTS WILL BE FROM SEVERE TSTMS APPROACHING FROM THE
WEST. CURRENT TIMING TAKES THE QLCS THROUGH KSAV ROUGHLY 02-04Z
AND KCHS 03-05Z. GUSTY WINDS...HAIL...AND VERY HEAVY RAIN WILL
LIKELY ACCOMPANY THESE STORMS. HIGHEST CONFIDENCE FOR SEVERE
IMPACTS WILL BE AT KSAV. WILL CARRY 2SM TSRA BR TEMPO 1/2SM +TSRA
FG SCT010 BKN025CB TO COVER FOR NOW. AT KCHS...ITS A BIT MORE
UNCERTAIN IF THE TSTMS WILL BE WEAKENING AS THEY APPROACH THE
TERMINAL. WILL CARRY TEMPO 3SM TSRA TEMPO 1SM TSRA FOR NOW.
AMENDMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT. STILL A POTENTIAL FOR LOW CLOUDS TO DEVELOP LATE.
OTHERWISE VFR.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KCHS 252306
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
706 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS LIKELY THIS EVENING...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SEVERE THUNDERSTORM WATCH 117 HAS BEEN ISSUED FOR ALL OF SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA UNTIL MIDNIGHT. GRIDS/TEXT
PRODUCTS HAVE BEEN UPDATED TO REFLECT THE WATCH AND SHORT TERM
TERM TRENDS. PRIMARY HAZARDS WILL BE LARGE HAIL...DAMAGING WINDS
AND FREQUENT CLOUD TO GROUND LIGHTNING ALONG WITH AN ISOLATED
TORNADO. INITIAL MODE WILL BE SUPERCELLS MOVING INTO THE WESTERN
ZONES FOLLOWED BY A QLCS MOVING ACROSS MUCH OF THE FORECAST AREA.

THERE IS POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. UPDATES WILL BE ISSUED AS NEEDED.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
SHORT TERM IMPACTS WILL BE FROM SEVERE TSTMS APPROACHING FROM THE
WEST. CURRENT TIMING TAKES THE QLCS THROUGH KSAV ROUGHLY 02-04Z
AND KCHS 03-05Z. GUSTY WINDS...HAIL...AND VERY HEAVY RAIN WILL
LIKELY ACCOMPANY THESE STORMS. HIGHEST CONFIDENCE FOR SEVERE
IMPACTS WILL BE AT KSAV. WILL CARRY 2SM TSRA BR TEMPO 1/2SM +TSRA
FG SCT010 BKN025CB TO COVER FOR NOW. AT KCHS...ITS A BIT MORE
UNCERTAIN IF THE TSTMS WILL BE WEAKENING AS THEY APPROACH THE
TERMINAL. WILL CARRY TEMPO 3SM TSRA TEMPO 1SM TSRA FOR NOW.
AMENDMENTS WILL MOST LIKELY BE NEEDED AS TRENDS BECOME A BIT MORE
APPARENT. STILL A POTENTIAL FOR LOW CLOUDS TO DEVELOP LATE.
OTHERWISE VFR.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KCHS 252237
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
637 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS LIKELY THIS EVENING...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SEVERE THUNDERSTORM WATCH 117 HAS BEEN ISSUED FOR ALL OF SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA UNTIL MIDNIGHT. GRIDS/TEXT
PRODUCTS HAVE BEEN UPDATED TO REFLECT THE WATCH AND SHORT TERM
TERM TRENDS. PRIMARY HAZARDS WILL BE LARGE HAIL...DAMAGING WINDS
AND FREQUENT CLOUD TO GROUND LIGHTNING ALONG WITH AN ISOLATED
TORNADO. INITIAL MODE WILL BE SUPERCELLS MOVING INTO THE WESTERN
ZONES FOLLOWED BY A QLCS MOVING ACROSS MUCH OF THE FORECAST AREA.

THERE IS POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. UPDATES WILL BE ISSUED AS NEEDED.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KCHS 252237
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
637 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS LIKELY THIS EVENING...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SEVERE THUNDERSTORM WATCH 117 HAS BEEN ISSUED FOR ALL OF SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA UNTIL MIDNIGHT. GRIDS/TEXT
PRODUCTS HAVE BEEN UPDATED TO REFLECT THE WATCH AND SHORT TERM
TERM TRENDS. PRIMARY HAZARDS WILL BE LARGE HAIL...DAMAGING WINDS
AND FREQUENT CLOUD TO GROUND LIGHTNING ALONG WITH AN ISOLATED
TORNADO. INITIAL MODE WILL BE SUPERCELLS MOVING INTO THE WESTERN
ZONES FOLLOWED BY A QLCS MOVING ACROSS MUCH OF THE FORECAST AREA.

THERE IS POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. UPDATES WILL BE ISSUED AS NEEDED.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KCHS 252237
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
637 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS LIKELY THIS EVENING...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SEVERE THUNDERSTORM WATCH 117 HAS BEEN ISSUED FOR ALL OF SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA UNTIL MIDNIGHT. GRIDS/TEXT
PRODUCTS HAVE BEEN UPDATED TO REFLECT THE WATCH AND SHORT TERM
TERM TRENDS. PRIMARY HAZARDS WILL BE LARGE HAIL...DAMAGING WINDS
AND FREQUENT CLOUD TO GROUND LIGHTNING ALONG WITH AN ISOLATED
TORNADO. INITIAL MODE WILL BE SUPERCELLS MOVING INTO THE WESTERN
ZONES FOLLOWED BY A QLCS MOVING ACROSS MUCH OF THE FORECAST AREA.

THERE IS POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. UPDATES WILL BE ISSUED AS NEEDED.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KCHS 252237
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
637 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS LIKELY THIS EVENING...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SEVERE THUNDERSTORM WATCH 117 HAS BEEN ISSUED FOR ALL OF SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA UNTIL MIDNIGHT. GRIDS/TEXT
PRODUCTS HAVE BEEN UPDATED TO REFLECT THE WATCH AND SHORT TERM
TERM TRENDS. PRIMARY HAZARDS WILL BE LARGE HAIL...DAMAGING WINDS
AND FREQUENT CLOUD TO GROUND LIGHTNING ALONG WITH AN ISOLATED
TORNADO. INITIAL MODE WILL BE SUPERCELLS MOVING INTO THE WESTERN
ZONES FOLLOWED BY A QLCS MOVING ACROSS MUCH OF THE FORECAST AREA.

THERE IS POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. UPDATES WILL BE ISSUED AS NEEDED.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KCHS 252237
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
637 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS LIKELY THIS EVENING...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SEVERE THUNDERSTORM WATCH 117 HAS BEEN ISSUED FOR ALL OF SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA UNTIL MIDNIGHT. GRIDS/TEXT
PRODUCTS HAVE BEEN UPDATED TO REFLECT THE WATCH AND SHORT TERM
TERM TRENDS. PRIMARY HAZARDS WILL BE LARGE HAIL...DAMAGING WINDS
AND FREQUENT CLOUD TO GROUND LIGHTNING ALONG WITH AN ISOLATED
TORNADO. INITIAL MODE WILL BE SUPERCELLS MOVING INTO THE WESTERN
ZONES FOLLOWED BY A QLCS MOVING ACROSS MUCH OF THE FORECAST AREA.

THERE IS POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. UPDATES WILL BE ISSUED AS NEEDED.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KCHS 252237
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
637 PM EDT SAT APR 25 2015

...SEVERE THUNDERSTORMS LIKELY THIS EVENING...

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SEVERE THUNDERSTORM WATCH 117 HAS BEEN ISSUED FOR ALL OF SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA UNTIL MIDNIGHT. GRIDS/TEXT
PRODUCTS HAVE BEEN UPDATED TO REFLECT THE WATCH AND SHORT TERM
TERM TRENDS. PRIMARY HAZARDS WILL BE LARGE HAIL...DAMAGING WINDS
AND FREQUENT CLOUD TO GROUND LIGHTNING ALONG WITH AN ISOLATED
TORNADO. INITIAL MODE WILL BE SUPERCELLS MOVING INTO THE WESTERN
ZONES FOLLOWED BY A QLCS MOVING ACROSS MUCH OF THE FORECAST AREA.

THERE IS POTENTIAL FOR THIS TO BE A SIGNIFICANT SEVERE WEATHER
EVENT...ESPECIALLY WEST OF THE I-95 CORRIDOR. WE CONTINUE TO
MONITOR TRENDS CAREFULLY. UPDATES WILL BE ISSUED AS NEEDED.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KCHS 252135
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
535 PM EDT SAT APR 25 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MESOSCALE UPDATE...A QUICK UPDATE HAS BEEN ISSUED TO REDEFINE
POPS A BIT MORE BASED ON CURRENT RADAR TRENDS AND SHORT TERM MODEL
DATA. LOOKS LIKE THE POTENTIAL FOR SEVERE WEATHER IS INCREASING AS
INSTABILITY CONTINUES TO BUILD AHEAD OF A CORRIDOR OF ENHANCED
UPPER FORCING. BASED ON LATEST DATA...THE RISK FOR SEVERE TSTMS
WILL BE EXPANDED NORTH TO WALTERBORO-KIAWAH ISLAND. STILL THINK
THE CHARLESTON METRO AREA WILL STAY NORTH OF THE QLCS...BUT IT
COULD BE CLOSE. WILL GO AHEAD AND INTRODUCE DAMAGING WINDS
ATTRIBUTE FOR THE ABOVE MENTIONED AREAS. A SEVERE TSTM OR TORNADO
WATCH MAY BE NEEDED OVER THE COMING HOURS.

A RATHER SIGNIFICANT NULL IN CONVECTION IS IN PROGRESS ACROSS THE
REGION LATE THIS AFTERNOON AS WEAK SUBSIDENCE HAS OVERSPREAD THE
AREA IN THE WAKE OF A WEAK MID-LEVEL DISTURBANCE. SATELLITE SHOWS
SOME SIGNIFICANT BREAKS IN THE CLOUD CANOPY OVER GEORGIA WHICH IS
HELPING TO PUSH TEMPERATURES BACK INTO THE UPPER 70S TO LOWER 80S
ACROSS SOUTHEAST GEORGIA WITH MID 80S ALONG THE ALTAMAHA RIVER.
THE ATMOSPHERE ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA WILL CONTINUE TO DESTABILIZE OVER THE NEXT FEW HOURS AS
POCKETS OF FOCUSED INSOLATION HELP TO DRIVE TEMPERATURES UP AS
DEWPOINTS RISE INTO THE LOWER 70S. MODIFIED RAP/H3R POINT
SOUNDINGS SUPPORT SBCAPES NEAR 2000 J/KG WITH LIFTED INDICES AS
LOW AS -4 TO -5C AND SHOWALTER INDICES -2 TO -3C--MODERATE VALUES
FOR LATE APRIL. LOW-LEVEL CONVERGENCE IS PROGGED TO INCREASE
ACROSS CENTRAL GEORGIA OVER THE NEXT FEW HOURS AS UPPER FORCING
ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE UPPER JET
OVERSPREAD THE DEEP SOUTH. KMXX/KJGX RADAR TRENDS ALREADY SHOW A
RECENT INCREASE IN SHOWER/TSTM ACTIVITY ALONG THE ALABAMA/GEORGIA
LINE...WHICH SUGGESTS THE FORCING WITH THE UPPER JET IS FINALLY
BEGINNING TO CATCH UP TO THE RIBBON OF HIGHER INSTABILITY THAT IS
BEGINNING TO EXPAND OVER SOUTHERN GEORGIA INTO FAR SOUTHERN SOUTH
CAROLINA.

THE MAIN QUESTION FOR THE EVENING HOURS IS HOW FOCUSED WITH ANY
RISK FOR SEVERE WEATHER BE. HIGH RESOLUTION MODELS...INCLUDING THE
H3R...HAVE BEEN INDICATING SOME SORT OF QLCS MOVING ACROSS
SOUTHEAST GEORGIA AND POSSIBLY AS FAR NORTH AS BEAUFORT OVER THE
NEXT SEVERAL HOURS AS THE CORRIDOR OF JET ENHANCED UPPER FORCING
TRAVERSES THE AREA. 0-6KM BULK SHEAR OF 55-65 KT IS CERTAINLY
SUPPORTIVE OF CONVECTIVE ORGANIZATION WITH POSSIBLE SUPERCELLS...
BUT THE EVENTUAL DEGREE OF INSTABILITY AND DEEP LAYERED FORCING
WILL BE ULTIMATE DETERMINING FACTORS ON HOW CONCENTRATED THE
SEVERE THREAT WILL BECOME. GIVEN THE CONSISTENT TRENDS NOTED IN
THE HIGH RESOLUTION MODELS ALL DAY...ITS HARD TO IGNORE THE
QLCS/BOW ECHO SIGNAL NOTED IN THE MODEL REFLECTIVITY PROGS.
CONVECTIVE TRENDS CONTINUE TO BE MONITORED AND A SEVERE TSTM OR
TORNADO WATCH MAY EVENTUALLY BE NEEDED FOR PARTS OF THE FORECAST
AREA OVER THE NEXT FEW HOURS.

THE PRIMARY HAZARDS LOOK TO BE DAMAGING WINDS...BUT ISOLATED
TORNADOES CAN NOT BE RULED OUT GIVEN THE DEGREE OF 0-1KM SR-
HELICITY IN PLACE. THE RISK FOR SEVERE WEATHER LOOKS TO BE THE
HIGHEST ROUGHLY ALONG/SOUTH OF A METTER-SPRINGFIELD-BEAUFORT
LINE...INCLUDING THE SAVANNAH METRO AREA. THE SEVERE PROBABILITIES
DROP OFF QUITE A BIT NORTH OF THIS LINE...INCLUDING THE
CHARLESTON TRI-COUNTY AREA.

WILL CARRY CHANCE TO LIKELY POPS ACROSS THE AREA THIS EVENING...
HIGHEST SOUTH OF THE I-16 CORRIDOR. WILL REFRAIN FROM INCLUDING
SEVERE WEATHER ATTRIBUTES IN THE GRIDDED AND TEXT FORECASTS FOR
NOW UNTIL CONVECTIVE TRENDS BECOME A BIT MORE APPARENT. ONCE THE
QLCS EXITS THE COAST...MAINLY DRY CONDITIONS WILL PREVAIL WITH
CLEARING SKIES. THE BOUNDARY LAYER LOOKS TO REMAIN COUPLED THROUGH
THE NIGHT WITH MODEST LOW-LEVEL JETTING REMAINING IN PLACE. THE
RISK FOR FOG LOOKS LOW AS A RESULT...BUT SOME AREAS OF LOW STRATUS
COULD DEVELOP JUST BEFORE SUNRISE...ESPECIALLY IN SOUTHEAST
GEORGIA. LOWS WILL ONLY DROP INTO THE UPPER 60S WITH A FEW MID 60S
POSSIBLE FOR AREAS BORDERING THE SOUTHERN/EASTERN MIDLANDS AND THE
SANTEE RIVER.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KCHS 252135
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
535 PM EDT SAT APR 25 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MESOSCALE UPDATE...A QUICK UPDATE HAS BEEN ISSUED TO REDEFINE
POPS A BIT MORE BASED ON CURRENT RADAR TRENDS AND SHORT TERM MODEL
DATA. LOOKS LIKE THE POTENTIAL FOR SEVERE WEATHER IS INCREASING AS
INSTABILITY CONTINUES TO BUILD AHEAD OF A CORRIDOR OF ENHANCED
UPPER FORCING. BASED ON LATEST DATA...THE RISK FOR SEVERE TSTMS
WILL BE EXPANDED NORTH TO WALTERBORO-KIAWAH ISLAND. STILL THINK
THE CHARLESTON METRO AREA WILL STAY NORTH OF THE QLCS...BUT IT
COULD BE CLOSE. WILL GO AHEAD AND INTRODUCE DAMAGING WINDS
ATTRIBUTE FOR THE ABOVE MENTIONED AREAS. A SEVERE TSTM OR TORNADO
WATCH MAY BE NEEDED OVER THE COMING HOURS.

A RATHER SIGNIFICANT NULL IN CONVECTION IS IN PROGRESS ACROSS THE
REGION LATE THIS AFTERNOON AS WEAK SUBSIDENCE HAS OVERSPREAD THE
AREA IN THE WAKE OF A WEAK MID-LEVEL DISTURBANCE. SATELLITE SHOWS
SOME SIGNIFICANT BREAKS IN THE CLOUD CANOPY OVER GEORGIA WHICH IS
HELPING TO PUSH TEMPERATURES BACK INTO THE UPPER 70S TO LOWER 80S
ACROSS SOUTHEAST GEORGIA WITH MID 80S ALONG THE ALTAMAHA RIVER.
THE ATMOSPHERE ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA WILL CONTINUE TO DESTABILIZE OVER THE NEXT FEW HOURS AS
POCKETS OF FOCUSED INSOLATION HELP TO DRIVE TEMPERATURES UP AS
DEWPOINTS RISE INTO THE LOWER 70S. MODIFIED RAP/H3R POINT
SOUNDINGS SUPPORT SBCAPES NEAR 2000 J/KG WITH LIFTED INDICES AS
LOW AS -4 TO -5C AND SHOWALTER INDICES -2 TO -3C--MODERATE VALUES
FOR LATE APRIL. LOW-LEVEL CONVERGENCE IS PROGGED TO INCREASE
ACROSS CENTRAL GEORGIA OVER THE NEXT FEW HOURS AS UPPER FORCING
ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE UPPER JET
OVERSPREAD THE DEEP SOUTH. KMXX/KJGX RADAR TRENDS ALREADY SHOW A
RECENT INCREASE IN SHOWER/TSTM ACTIVITY ALONG THE ALABAMA/GEORGIA
LINE...WHICH SUGGESTS THE FORCING WITH THE UPPER JET IS FINALLY
BEGINNING TO CATCH UP TO THE RIBBON OF HIGHER INSTABILITY THAT IS
BEGINNING TO EXPAND OVER SOUTHERN GEORGIA INTO FAR SOUTHERN SOUTH
CAROLINA.

THE MAIN QUESTION FOR THE EVENING HOURS IS HOW FOCUSED WITH ANY
RISK FOR SEVERE WEATHER BE. HIGH RESOLUTION MODELS...INCLUDING THE
H3R...HAVE BEEN INDICATING SOME SORT OF QLCS MOVING ACROSS
SOUTHEAST GEORGIA AND POSSIBLY AS FAR NORTH AS BEAUFORT OVER THE
NEXT SEVERAL HOURS AS THE CORRIDOR OF JET ENHANCED UPPER FORCING
TRAVERSES THE AREA. 0-6KM BULK SHEAR OF 55-65 KT IS CERTAINLY
SUPPORTIVE OF CONVECTIVE ORGANIZATION WITH POSSIBLE SUPERCELLS...
BUT THE EVENTUAL DEGREE OF INSTABILITY AND DEEP LAYERED FORCING
WILL BE ULTIMATE DETERMINING FACTORS ON HOW CONCENTRATED THE
SEVERE THREAT WILL BECOME. GIVEN THE CONSISTENT TRENDS NOTED IN
THE HIGH RESOLUTION MODELS ALL DAY...ITS HARD TO IGNORE THE
QLCS/BOW ECHO SIGNAL NOTED IN THE MODEL REFLECTIVITY PROGS.
CONVECTIVE TRENDS CONTINUE TO BE MONITORED AND A SEVERE TSTM OR
TORNADO WATCH MAY EVENTUALLY BE NEEDED FOR PARTS OF THE FORECAST
AREA OVER THE NEXT FEW HOURS.

THE PRIMARY HAZARDS LOOK TO BE DAMAGING WINDS...BUT ISOLATED
TORNADOES CAN NOT BE RULED OUT GIVEN THE DEGREE OF 0-1KM SR-
HELICITY IN PLACE. THE RISK FOR SEVERE WEATHER LOOKS TO BE THE
HIGHEST ROUGHLY ALONG/SOUTH OF A METTER-SPRINGFIELD-BEAUFORT
LINE...INCLUDING THE SAVANNAH METRO AREA. THE SEVERE PROBABILITIES
DROP OFF QUITE A BIT NORTH OF THIS LINE...INCLUDING THE
CHARLESTON TRI-COUNTY AREA.

WILL CARRY CHANCE TO LIKELY POPS ACROSS THE AREA THIS EVENING...
HIGHEST SOUTH OF THE I-16 CORRIDOR. WILL REFRAIN FROM INCLUDING
SEVERE WEATHER ATTRIBUTES IN THE GRIDDED AND TEXT FORECASTS FOR
NOW UNTIL CONVECTIVE TRENDS BECOME A BIT MORE APPARENT. ONCE THE
QLCS EXITS THE COAST...MAINLY DRY CONDITIONS WILL PREVAIL WITH
CLEARING SKIES. THE BOUNDARY LAYER LOOKS TO REMAIN COUPLED THROUGH
THE NIGHT WITH MODEST LOW-LEVEL JETTING REMAINING IN PLACE. THE
RISK FOR FOG LOOKS LOW AS A RESULT...BUT SOME AREAS OF LOW STRATUS
COULD DEVELOP JUST BEFORE SUNRISE...ESPECIALLY IN SOUTHEAST
GEORGIA. LOWS WILL ONLY DROP INTO THE UPPER 60S WITH A FEW MID 60S
POSSIBLE FOR AREAS BORDERING THE SOUTHERN/EASTERN MIDLANDS AND THE
SANTEE RIVER.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 252126
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
526 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD ACROSS THE
FORECAST AREA THIS EVENING. REGIONAL RADAR LOOP AS OF 2130Z SHOWS
CONVECTION MOVING EAST/NORTHEAST INTO SOUTHERN AND CENTRAL GEORGIA.
THE STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST SOUTH OF
THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST HI-
RESOLUTION MODEL REFLECTIVITY. EVEN SO...STILL CANNOT RULE OUT
SEEING SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING
PROGRESSES. SATELLITE IMAGERY SHOWS SOME BREAKS IN THE CLOUDS IN
THE CSRA WHICH SHOULD INCREASE INSTABILITY. SHEAR VALUES REMAIN
HIGH THROUGH THE EVENING...WHICH WOULD HELP SUPPORT ROTATING
STORMS IF ANY CAN PUSH INTO THE AREA. CURRENT MESOANALYSIS ALSO
SHOWS HIGHEST PWAT VALUES IN OUR SOUTHERN AND EASTERN COUNTIES.
SPC HAS TRIMMED BACK THE SLIGHT RISK TO COVER ONLY OUR SOUTHERN
AND EASTERN COUNTIES WITH A MARGINAL RISK FURTHER NORTH AND WEST.

MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE GULF SYSTEM
MOVES SOUTH OF THE AREA TONIGHT. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE GFS AND NAM MOS PLUS SREF GUIDANCE GENERALLY INDICATE MVFR OR
IFR CEILINGS TONIGHT. WE LEANED TOWARD THE MORE OPTIMISTIC
GUIDANCE THINKING MIXING IN THE WARM SECTOR SOUTH OF THE BOUNDARY
WOULD HELP HOLD UP CEILINGS. SHALLOW MOISTURE AND A LACK OF
SIGNIFICANT UPPER-LEVEL FORCING SHOULD HELP LIMIT THUNDERSTORM
COVERAGE. THE CHANCE IS TOO LOW TO INCLUDE IN THE TERMINAL
FORECASTS AT THIS TIME. THE LOW-LEVEL JET SUPPORTS KEEPING LLWS IN
THE TERMINAL FORECASTS TONIGHT. USED THE NAM FOR THE MAGNITUDE OF
THE SHEAR. THE MODELS SHOW THE BOUNDARY SINKING SOUTHWARD SUNDAY
BUT WITH SHALLOW MOISTURE. THE THUNDERSTORM CHANCE STILL APPEARED
TOO LOW TO INCLUDE IN THE TERMINAL FORECAST. BASED ON THE GFS
LAMP AND THE NAM BUFKIT MOMENTUM TRANSFER TOOL WE INCLUDED WIND
GUSTS NEAR 24 KNOTS.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KGSP 252046
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
446 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 440 PM EDT SATURDAY...CONTINUED TO ADJUST POPS DOWN OVER THE
NEXT FEW HOURS AS MODELS INDICATE LULL IN PRECIP AS WEDGE HOLDS.
LATEST SPC MESO ANALYSIS DOES INDICATE INCREASED INSTABILITY
GRADIENT TO THE SOUTH ALONG THE I20 CORRIDOR WITH THE MOST RECENT
NAM GUID SLIDING SAID AXIS NORTHWARD INTO THE SOUTHERN SC PIEDMONT
AND PORTIONS OF NORTHEAST GA LATER THIS AFTERNOON/EVENING.  THUS...
CONFIDENCE IS LOW THAT MUCH IN THE WAY OF CONVECTIVE SHOWERS/THUNDER
ACTIVITY WILL OCCUR IN THE NEXT FEW HOURS...BUT PROBABILITIES DO
INCREASE LATER THIS EVENING AS THE WEDGE ERODES.  ALSO CONTINUING TO
MONITOR UPSTREAM ACTIVITY OVER THE OH VALLEY REGION WHERE MCS
DEVELOPMENT IS EXPECTED...WITH A SOUTHEASTERN TRACK FAVORED IN SOME
GUIDANCE.  THIS WOULD SUPPORT A LINE OF STRONG/SEVERE CONVECTION
MOVING INTO THE NC MOUNTAINS/FOOTHILLS AFTER MIDNIGHT.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
AT KCLT...LOW CONFIDENCE FORECAST...WITH MODEL GUIDANCE QUITE
DIVERGENT. OBSERVATIONS SHOW IFR CIG RESTRICTION...BUT VSBY HAS
IMPROVED BEHIND DEPARTING RAINFALL. MODEL TIME HEIGHTS SUPPORT BRIEF
CIG IMPROVEMENT TO LOW VFR THIS EVENING BEFORE LOWERING TO AT LEAST
MVFR LATE TONIGHT INTO SUNDAY MORNING. GUIDANCE SUPPORTS AN MVFR
VSBY LATE THIS EVENING...BUT SUGGEST A RETURN TO VFR TOWARD DAWN...
OSTENSIBLY DUE TO NE WINDS THAT SET UP OVERNIGHT AS A COLD FRONT
ARRIVES FROM THE N. CONVECTIVE CHANCES APPEAR BEST OVERNIGHT AS THE
FRONT APPROACHES.

ELSEWHERE...CONFIDENCE IS LIMITED AS TRENDS DEPART FORM PREVIOUS
FORECAST...AND MODEL SOLUTIONS DIVERGE. OBSERVED CIG RESTRICTIONS
MAY IMPROVE THIS EVENING BASED ON MODEL TIME HEIGHTS...BUT PROBABLY
NOT AS MUCH AS A MODEL BLEND WOULD SUGGEST. VSBY IMPROVEMENT HAS
BEEN NOTED AS RAINFALL MOVES OFF TO THE EAST...AND THIS TREND IS
EXPECTED OT CONTINUE. TIME HEIGHTS SHOW CIGS LOWERING AGAIN TOWARD
DAWN...AND REMAINING LOW INTO SUNDAY MORNING. VSBY RESTRICTIONS
APPEAR TO RETURN AT KHKY LATE THIS EVENING...THEN END AS A BACK DOOR
COLD FRONT ARRIVES BEFORE DAWN VEERING THE WIND TO THE NE. MODEL
DATA SUPPORTS KAND HAVING A DAYBREAK VSBY RESTRICTION...BUT MODEL
WINDS REMAIN UP...FAVORING VFR. CONVECTIVE CHANCES NOW APPEAR TO BE
BEST OVERNIGHT AHEAD OF THE COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            20-02Z        02-08Z        08-14Z        14-18Z
KCLT       HIGH  95%     MED   61%     MED   61%     HIGH  90%
KGSP       MED   76%     HIGH  95%     MED   70%     MED   60%
KAVL       MED   67%     MED   63%     LOW   57%     MED   77%
KHKY       HIGH  95%     LOW   58%     MED   66%     HIGH  92%
KGMU       MED   76%     HIGH  92%     MED   66%     MED   60%
KAND       HIGH  87%     HIGH  96%     LOW   56%     MED   62%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...CDG/JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...JAT




000
FXUS62 KGSP 252046
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
446 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 440 PM EDT SATURDAY...CONTINUED TO ADJUST POPS DOWN OVER THE
NEXT FEW HOURS AS MODELS INDICATE LULL IN PRECIP AS WEDGE HOLDS.
LATEST SPC MESO ANALYSIS DOES INDICATE INCREASED INSTABILITY
GRADIENT TO THE SOUTH ALONG THE I20 CORRIDOR WITH THE MOST RECENT
NAM GUID SLIDING SAID AXIS NORTHWARD INTO THE SOUTHERN SC PIEDMONT
AND PORTIONS OF NORTHEAST GA LATER THIS AFTERNOON/EVENING.  THUS...
CONFIDENCE IS LOW THAT MUCH IN THE WAY OF CONVECTIVE SHOWERS/THUNDER
ACTIVITY WILL OCCUR IN THE NEXT FEW HOURS...BUT PROBABILITIES DO
INCREASE LATER THIS EVENING AS THE WEDGE ERODES.  ALSO CONTINUING TO
MONITOR UPSTREAM ACTIVITY OVER THE OH VALLEY REGION WHERE MCS
DEVELOPMENT IS EXPECTED...WITH A SOUTHEASTERN TRACK FAVORED IN SOME
GUIDANCE.  THIS WOULD SUPPORT A LINE OF STRONG/SEVERE CONVECTION
MOVING INTO THE NC MOUNTAINS/FOOTHILLS AFTER MIDNIGHT.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
AT KCLT...LOW CONFIDENCE FORECAST...WITH MODEL GUIDANCE QUITE
DIVERGENT. OBSERVATIONS SHOW IFR CIG RESTRICTION...BUT VSBY HAS
IMPROVED BEHIND DEPARTING RAINFALL. MODEL TIME HEIGHTS SUPPORT BRIEF
CIG IMPROVEMENT TO LOW VFR THIS EVENING BEFORE LOWERING TO AT LEAST
MVFR LATE TONIGHT INTO SUNDAY MORNING. GUIDANCE SUPPORTS AN MVFR
VSBY LATE THIS EVENING...BUT SUGGEST A RETURN TO VFR TOWARD DAWN...
OSTENSIBLY DUE TO NE WINDS THAT SET UP OVERNIGHT AS A COLD FRONT
ARRIVES FROM THE N. CONVECTIVE CHANCES APPEAR BEST OVERNIGHT AS THE
FRONT APPROACHES.

ELSEWHERE...CONFIDENCE IS LIMITED AS TRENDS DEPART FORM PREVIOUS
FORECAST...AND MODEL SOLUTIONS DIVERGE. OBSERVED CIG RESTRICTIONS
MAY IMPROVE THIS EVENING BASED ON MODEL TIME HEIGHTS...BUT PROBABLY
NOT AS MUCH AS A MODEL BLEND WOULD SUGGEST. VSBY IMPROVEMENT HAS
BEEN NOTED AS RAINFALL MOVES OFF TO THE EAST...AND THIS TREND IS
EXPECTED OT CONTINUE. TIME HEIGHTS SHOW CIGS LOWERING AGAIN TOWARD
DAWN...AND REMAINING LOW INTO SUNDAY MORNING. VSBY RESTRICTIONS
APPEAR TO RETURN AT KHKY LATE THIS EVENING...THEN END AS A BACK DOOR
COLD FRONT ARRIVES BEFORE DAWN VEERING THE WIND TO THE NE. MODEL
DATA SUPPORTS KAND HAVING A DAYBREAK VSBY RESTRICTION...BUT MODEL
WINDS REMAIN UP...FAVORING VFR. CONVECTIVE CHANCES NOW APPEAR TO BE
BEST OVERNIGHT AHEAD OF THE COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            20-02Z        02-08Z        08-14Z        14-18Z
KCLT       HIGH  95%     MED   61%     MED   61%     HIGH  90%
KGSP       MED   76%     HIGH  95%     MED   70%     MED   60%
KAVL       MED   67%     MED   63%     LOW   57%     MED   77%
KHKY       HIGH  95%     LOW   58%     MED   66%     HIGH  92%
KGMU       MED   76%     HIGH  92%     MED   66%     MED   60%
KAND       HIGH  87%     HIGH  96%     LOW   56%     MED   62%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...CDG/JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...JAT



000
FXUS62 KGSP 252046
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
446 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF 440 PM EDT SATURDAY...CONTINUED TO ADJUST POPS DOWN OVER THE
NEXT FEW HOURS AS MODELS INDICATE LULL IN PRECIP AS WEDGE HOLDS.
LATEST SPC MESO ANALYSIS DOES INDICATE INCREASED INSTABILITY
GRADIENT TO THE SOUTH ALONG THE I20 CORRIDOR WITH THE MOST RECENT
NAM GUID SLIDING SAID AXIS NORTHWARD INTO THE SOUTHERN SC PIEDMONT
AND PORTIONS OF NORTHEAST GA LATER THIS AFTERNOON/EVENING.  THUS...
CONFIDENCE IS LOW THAT MUCH IN THE WAY OF CONVECTIVE SHOWERS/THUNDER
ACTIVITY WILL OCCUR IN THE NEXT FEW HOURS...BUT PROBABILITIES DO
INCREASE LATER THIS EVENING AS THE WEDGE ERODES.  ALSO CONTINUING TO
MONITOR UPSTREAM ACTIVITY OVER THE OH VALLEY REGION WHERE MCS
DEVELOPMENT IS EXPECTED...WITH A SOUTHEASTERN TRACK FAVORED IN SOME
GUIDANCE.  THIS WOULD SUPPORT A LINE OF STRONG/SEVERE CONVECTION
MOVING INTO THE NC MOUNTAINS/FOOTHILLS AFTER MIDNIGHT.

PREVIOUS DISCUSSION...

AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
AT KCLT...LOW CONFIDENCE FORECAST...WITH MODEL GUIDANCE QUITE
DIVERGENT. OBSERVATIONS SHOW IFR CIG RESTRICTION...BUT VSBY HAS
IMPROVED BEHIND DEPARTING RAINFALL. MODEL TIME HEIGHTS SUPPORT BRIEF
CIG IMPROVEMENT TO LOW VFR THIS EVENING BEFORE LOWERING TO AT LEAST
MVFR LATE TONIGHT INTO SUNDAY MORNING. GUIDANCE SUPPORTS AN MVFR
VSBY LATE THIS EVENING...BUT SUGGEST A RETURN TO VFR TOWARD DAWN...
OSTENSIBLY DUE TO NE WINDS THAT SET UP OVERNIGHT AS A COLD FRONT
ARRIVES FROM THE N. CONVECTIVE CHANCES APPEAR BEST OVERNIGHT AS THE
FRONT APPROACHES.

ELSEWHERE...CONFIDENCE IS LIMITED AS TRENDS DEPART FORM PREVIOUS
FORECAST...AND MODEL SOLUTIONS DIVERGE. OBSERVED CIG RESTRICTIONS
MAY IMPROVE THIS EVENING BASED ON MODEL TIME HEIGHTS...BUT PROBABLY
NOT AS MUCH AS A MODEL BLEND WOULD SUGGEST. VSBY IMPROVEMENT HAS
BEEN NOTED AS RAINFALL MOVES OFF TO THE EAST...AND THIS TREND IS
EXPECTED OT CONTINUE. TIME HEIGHTS SHOW CIGS LOWERING AGAIN TOWARD
DAWN...AND REMAINING LOW INTO SUNDAY MORNING. VSBY RESTRICTIONS
APPEAR TO RETURN AT KHKY LATE THIS EVENING...THEN END AS A BACK DOOR
COLD FRONT ARRIVES BEFORE DAWN VEERING THE WIND TO THE NE. MODEL
DATA SUPPORTS KAND HAVING A DAYBREAK VSBY RESTRICTION...BUT MODEL
WINDS REMAIN UP...FAVORING VFR. CONVECTIVE CHANCES NOW APPEAR TO BE
BEST OVERNIGHT AHEAD OF THE COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            20-02Z        02-08Z        08-14Z        14-18Z
KCLT       HIGH  95%     MED   61%     MED   61%     HIGH  90%
KGSP       MED   76%     HIGH  95%     MED   70%     MED   60%
KAVL       MED   67%     MED   63%     LOW   57%     MED   77%
KHKY       HIGH  95%     LOW   58%     MED   66%     HIGH  92%
KGMU       MED   76%     HIGH  92%     MED   66%     MED   60%
KAND       HIGH  87%     HIGH  96%     LOW   56%     MED   62%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...CDG/JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...JAT




000
FXUS62 KCHS 251957
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
357 PM EDT SAT APR 25 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A RATHER SIGNIFICANT NULL IN CONVECTION IS IN PROGRESS ACROSS THE
REGION LATE THIS AFTERNOON AS WEAK SUBSIDENCE HAS OVERSPREAD THE
AREA IN THE WAKE OF A WEAK MID-LEVEL DISTURBANCE. SATELLITE SHOWS
SOME SIGNIFICANT BREAKS IN THE CLOUD CANOPY OVER GEORGIA WHICH IS
HELPING TO PUSH TEMPERATURES BACK INTO THE UPPER 70S TO LOWER 80S
ACROSS SOUTHEAST GEORGIA WITH MID 80S ALONG THE ALTAMAHA RIVER.
THE ATMOSPHERE ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA WILL CONTINUE TO DESTABILIZE OVER THE NEXT FEW HOURS AS
POCKETS OF FOCUSED INSOLATION HELP TO DRIVE TEMPERATURES UP AS
DEWPOINTS RISE INTO THE LOWER 70S. MODIFIED RAP/H3R POINT
SOUNDINGS SUPPORT SBCAPES NEAR 2000 J/KG WITH LIFTED INDICES AS
LOW AS -4 TO -5C AND SHOWALTER INDICES -2 TO -3C--MODERATE VALUES
FOR LATE APRIL. LOW-LEVEL CONVERGENCE IS PROGGED TO INCREASE
ACROSS CENTRAL GEORGIA OVER THE NEXT FEW HOURS AS UPPER FORCING
ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE UPPER JET
OVERSPREAD THE DEEP SOUTH. KMXX/KJGX RADAR TRENDS ALREADY SHOW A
RECENT INCREASE IN SHOWER/TSTM ACTIVITY ALONG THE ALABAMA/GEORGIA
LINE...WHICH SUGGESTS THE FORCING WITH THE UPPER JET IS FINALLY
BEGINNING TO CATCH UP TO THE RIBBON OF HIGHER INSTABILITY THAT IS
BEGINNING TO EXPAND OVER SOUTHERN GEORGIA INTO FAR SOUTHERN SOUTH
CAROLINA.

THE MAIN QUESTION FOR THE EVENING HOURS IS HOW FOCUSED WITH ANY
RISK FOR SEVERE WEATHER BE. HIGH RESOLUTION MODELS...INCLUDING THE
H3R...HAVE BEEN INDICATING SOME SORT OF QLCS MOVING ACROSS
SOUTHEAST GEORGIA AND POSSIBLY AS FAR NORTH AS BEAUFORT OVER THE
NEXT SEVERAL HOURS AS THE CORRIDOR OF JET ENHANCED UPPER FORCING
TRAVERSES THE AREA. 0-6KM BULK SHEAR OF 55-65 KT IS CERTAINLY
SUPPORTIVE OF CONVECTIVE ORGANIZATION WITH POSSIBLE SUPERCELLS...
BUT THE EVENTUAL DEGREE OF INSTABILITY AND DEEP LAYERED FORCING
WILL BE ULTIMATE DETERMINING FACTORS ON HOW CONCENTRATED THE
SEVERE THREAT WILL BECOME. GIVEN THE CONSISTENT TRENDS NOTED IN
THE HIGH RESOLUTION MODELS ALL DAY...ITS HARD TO IGNORE THE
QLCS/BOW ECHO SIGNAL NOTED IN THE MODEL REFLECTIVITY PROGS.
CONVECTIVE TRENDS CONTINUE TO BE MONITORED AND A SEVERE TSTM OR
TORNADO WATCH MAY EVENTUALLY BE NEEDED FOR PARTS OF THE FORECAST
AREA OVER THE NEXT FEW HOURS.

THE PRIMARY HAZARDS LOOK TO BE DAMAGING WINDS...BUT ISOLATED
TORNADOES CAN NOT BE RULED OUT GIVEN THE DEGREE OF 0-1KM SR-
HELICITY IN PLACE. THE RISK FOR SEVERE WEATHER LOOKS TO BE THE
HIGHEST ROUGHLY ALONG/SOUTH OF A METTER-SPRINGFIELD-BEAUFORT
LINE...INCLUDING THE SAVANNAH METRO AREA. THE SEVERE PROBABILITIES
DROP OFF QUITE A BIT NORTH OF THIS LINE...INCLUDING THE
CHARLESTON TRI-COUNTY AREA.

WILL CARRY CHANCE TO LIKELY POPS ACROSS THE AREA THIS EVENING...
HIGHEST SOUTH OF THE I-16 CORRIDOR. WILL REFRAIN FROM INCLUDING
SEVERE WEATHER ATTRIBUTES IN THE GRIDDED AND TEXT FORECASTS FOR
NOW UNTIL CONVECTIVE TRENDS BECOME A BIT MORE APPARENT. ONCE THE
QLCS EXITS THE COAST...MAINLY DRY CONDITIONS WILL PREVAIL WITH
CLEARING SKIES. THE BOUNDARY LAYER LOOKS TO REMAIN COUPLED THROUGH
THE NIGHT WITH MODEST LOW-LEVEL JETTING REMAINING IN PLACE. THE
RISK FOR FOG LOOKS LOW AS A RESULT...BUT SOME AREAS OF LOW STRATUS
COULD DEVELOP JUST BEFORE SUNRISE...ESPECIALLY IN SOUTHEAST
GEORGIA. LOWS WILL ONLY DROP INTO THE UPPER 60S WITH A FEW MID 60S
POSSIBLE FOR AREAS BORDERING THE SOUTHERN/EASTERN MIDLANDS AND THE
SANTEE RIVER.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST/DPB




000
FXUS62 KCHS 251957
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
357 PM EDT SAT APR 25 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A RATHER SIGNIFICANT NULL IN CONVECTION IS IN PROGRESS ACROSS THE
REGION LATE THIS AFTERNOON AS WEAK SUBSIDENCE HAS OVERSPREAD THE
AREA IN THE WAKE OF A WEAK MID-LEVEL DISTURBANCE. SATELLITE SHOWS
SOME SIGNIFICANT BREAKS IN THE CLOUD CANOPY OVER GEORGIA WHICH IS
HELPING TO PUSH TEMPERATURES BACK INTO THE UPPER 70S TO LOWER 80S
ACROSS SOUTHEAST GEORGIA WITH MID 80S ALONG THE ALTAMAHA RIVER.
THE ATMOSPHERE ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA WILL CONTINUE TO DESTABILIZE OVER THE NEXT FEW HOURS AS
POCKETS OF FOCUSED INSOLATION HELP TO DRIVE TEMPERATURES UP AS
DEWPOINTS RISE INTO THE LOWER 70S. MODIFIED RAP/H3R POINT
SOUNDINGS SUPPORT SBCAPES NEAR 2000 J/KG WITH LIFTED INDICES AS
LOW AS -4 TO -5C AND SHOWALTER INDICES -2 TO -3C--MODERATE VALUES
FOR LATE APRIL. LOW-LEVEL CONVERGENCE IS PROGGED TO INCREASE
ACROSS CENTRAL GEORGIA OVER THE NEXT FEW HOURS AS UPPER FORCING
ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE UPPER JET
OVERSPREAD THE DEEP SOUTH. KMXX/KJGX RADAR TRENDS ALREADY SHOW A
RECENT INCREASE IN SHOWER/TSTM ACTIVITY ALONG THE ALABAMA/GEORGIA
LINE...WHICH SUGGESTS THE FORCING WITH THE UPPER JET IS FINALLY
BEGINNING TO CATCH UP TO THE RIBBON OF HIGHER INSTABILITY THAT IS
BEGINNING TO EXPAND OVER SOUTHERN GEORGIA INTO FAR SOUTHERN SOUTH
CAROLINA.

THE MAIN QUESTION FOR THE EVENING HOURS IS HOW FOCUSED WITH ANY
RISK FOR SEVERE WEATHER BE. HIGH RESOLUTION MODELS...INCLUDING THE
H3R...HAVE BEEN INDICATING SOME SORT OF QLCS MOVING ACROSS
SOUTHEAST GEORGIA AND POSSIBLY AS FAR NORTH AS BEAUFORT OVER THE
NEXT SEVERAL HOURS AS THE CORRIDOR OF JET ENHANCED UPPER FORCING
TRAVERSES THE AREA. 0-6KM BULK SHEAR OF 55-65 KT IS CERTAINLY
SUPPORTIVE OF CONVECTIVE ORGANIZATION WITH POSSIBLE SUPERCELLS...
BUT THE EVENTUAL DEGREE OF INSTABILITY AND DEEP LAYERED FORCING
WILL BE ULTIMATE DETERMINING FACTORS ON HOW CONCENTRATED THE
SEVERE THREAT WILL BECOME. GIVEN THE CONSISTENT TRENDS NOTED IN
THE HIGH RESOLUTION MODELS ALL DAY...ITS HARD TO IGNORE THE
QLCS/BOW ECHO SIGNAL NOTED IN THE MODEL REFLECTIVITY PROGS.
CONVECTIVE TRENDS CONTINUE TO BE MONITORED AND A SEVERE TSTM OR
TORNADO WATCH MAY EVENTUALLY BE NEEDED FOR PARTS OF THE FORECAST
AREA OVER THE NEXT FEW HOURS.

THE PRIMARY HAZARDS LOOK TO BE DAMAGING WINDS...BUT ISOLATED
TORNADOES CAN NOT BE RULED OUT GIVEN THE DEGREE OF 0-1KM SR-
HELICITY IN PLACE. THE RISK FOR SEVERE WEATHER LOOKS TO BE THE
HIGHEST ROUGHLY ALONG/SOUTH OF A METTER-SPRINGFIELD-BEAUFORT
LINE...INCLUDING THE SAVANNAH METRO AREA. THE SEVERE PROBABILITIES
DROP OFF QUITE A BIT NORTH OF THIS LINE...INCLUDING THE
CHARLESTON TRI-COUNTY AREA.

WILL CARRY CHANCE TO LIKELY POPS ACROSS THE AREA THIS EVENING...
HIGHEST SOUTH OF THE I-16 CORRIDOR. WILL REFRAIN FROM INCLUDING
SEVERE WEATHER ATTRIBUTES IN THE GRIDDED AND TEXT FORECASTS FOR
NOW UNTIL CONVECTIVE TRENDS BECOME A BIT MORE APPARENT. ONCE THE
QLCS EXITS THE COAST...MAINLY DRY CONDITIONS WILL PREVAIL WITH
CLEARING SKIES. THE BOUNDARY LAYER LOOKS TO REMAIN COUPLED THROUGH
THE NIGHT WITH MODEST LOW-LEVEL JETTING REMAINING IN PLACE. THE
RISK FOR FOG LOOKS LOW AS A RESULT...BUT SOME AREAS OF LOW STRATUS
COULD DEVELOP JUST BEFORE SUNRISE...ESPECIALLY IN SOUTHEAST
GEORGIA. LOWS WILL ONLY DROP INTO THE UPPER 60S WITH A FEW MID 60S
POSSIBLE FOR AREAS BORDERING THE SOUTHERN/EASTERN MIDLANDS AND THE
SANTEE RIVER.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST/DPB




000
FXUS62 KCHS 251957
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
357 PM EDT SAT APR 25 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A RATHER SIGNIFICANT NULL IN CONVECTION IS IN PROGRESS ACROSS THE
REGION LATE THIS AFTERNOON AS WEAK SUBSIDENCE HAS OVERSPREAD THE
AREA IN THE WAKE OF A WEAK MID-LEVEL DISTURBANCE. SATELLITE SHOWS
SOME SIGNIFICANT BREAKS IN THE CLOUD CANOPY OVER GEORGIA WHICH IS
HELPING TO PUSH TEMPERATURES BACK INTO THE UPPER 70S TO LOWER 80S
ACROSS SOUTHEAST GEORGIA WITH MID 80S ALONG THE ALTAMAHA RIVER.
THE ATMOSPHERE ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA WILL CONTINUE TO DESTABILIZE OVER THE NEXT FEW HOURS AS
POCKETS OF FOCUSED INSOLATION HELP TO DRIVE TEMPERATURES UP AS
DEWPOINTS RISE INTO THE LOWER 70S. MODIFIED RAP/H3R POINT
SOUNDINGS SUPPORT SBCAPES NEAR 2000 J/KG WITH LIFTED INDICES AS
LOW AS -4 TO -5C AND SHOWALTER INDICES -2 TO -3C--MODERATE VALUES
FOR LATE APRIL. LOW-LEVEL CONVERGENCE IS PROGGED TO INCREASE
ACROSS CENTRAL GEORGIA OVER THE NEXT FEW HOURS AS UPPER FORCING
ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE UPPER JET
OVERSPREAD THE DEEP SOUTH. KMXX/KJGX RADAR TRENDS ALREADY SHOW A
RECENT INCREASE IN SHOWER/TSTM ACTIVITY ALONG THE ALABAMA/GEORGIA
LINE...WHICH SUGGESTS THE FORCING WITH THE UPPER JET IS FINALLY
BEGINNING TO CATCH UP TO THE RIBBON OF HIGHER INSTABILITY THAT IS
BEGINNING TO EXPAND OVER SOUTHERN GEORGIA INTO FAR SOUTHERN SOUTH
CAROLINA.

THE MAIN QUESTION FOR THE EVENING HOURS IS HOW FOCUSED WITH ANY
RISK FOR SEVERE WEATHER BE. HIGH RESOLUTION MODELS...INCLUDING THE
H3R...HAVE BEEN INDICATING SOME SORT OF QLCS MOVING ACROSS
SOUTHEAST GEORGIA AND POSSIBLY AS FAR NORTH AS BEAUFORT OVER THE
NEXT SEVERAL HOURS AS THE CORRIDOR OF JET ENHANCED UPPER FORCING
TRAVERSES THE AREA. 0-6KM BULK SHEAR OF 55-65 KT IS CERTAINLY
SUPPORTIVE OF CONVECTIVE ORGANIZATION WITH POSSIBLE SUPERCELLS...
BUT THE EVENTUAL DEGREE OF INSTABILITY AND DEEP LAYERED FORCING
WILL BE ULTIMATE DETERMINING FACTORS ON HOW CONCENTRATED THE
SEVERE THREAT WILL BECOME. GIVEN THE CONSISTENT TRENDS NOTED IN
THE HIGH RESOLUTION MODELS ALL DAY...ITS HARD TO IGNORE THE
QLCS/BOW ECHO SIGNAL NOTED IN THE MODEL REFLECTIVITY PROGS.
CONVECTIVE TRENDS CONTINUE TO BE MONITORED AND A SEVERE TSTM OR
TORNADO WATCH MAY EVENTUALLY BE NEEDED FOR PARTS OF THE FORECAST
AREA OVER THE NEXT FEW HOURS.

THE PRIMARY HAZARDS LOOK TO BE DAMAGING WINDS...BUT ISOLATED
TORNADOES CAN NOT BE RULED OUT GIVEN THE DEGREE OF 0-1KM SR-
HELICITY IN PLACE. THE RISK FOR SEVERE WEATHER LOOKS TO BE THE
HIGHEST ROUGHLY ALONG/SOUTH OF A METTER-SPRINGFIELD-BEAUFORT
LINE...INCLUDING THE SAVANNAH METRO AREA. THE SEVERE PROBABILITIES
DROP OFF QUITE A BIT NORTH OF THIS LINE...INCLUDING THE
CHARLESTON TRI-COUNTY AREA.

WILL CARRY CHANCE TO LIKELY POPS ACROSS THE AREA THIS EVENING...
HIGHEST SOUTH OF THE I-16 CORRIDOR. WILL REFRAIN FROM INCLUDING
SEVERE WEATHER ATTRIBUTES IN THE GRIDDED AND TEXT FORECASTS FOR
NOW UNTIL CONVECTIVE TRENDS BECOME A BIT MORE APPARENT. ONCE THE
QLCS EXITS THE COAST...MAINLY DRY CONDITIONS WILL PREVAIL WITH
CLEARING SKIES. THE BOUNDARY LAYER LOOKS TO REMAIN COUPLED THROUGH
THE NIGHT WITH MODEST LOW-LEVEL JETTING REMAINING IN PLACE. THE
RISK FOR FOG LOOKS LOW AS A RESULT...BUT SOME AREAS OF LOW STRATUS
COULD DEVELOP JUST BEFORE SUNRISE...ESPECIALLY IN SOUTHEAST
GEORGIA. LOWS WILL ONLY DROP INTO THE UPPER 60S WITH A FEW MID 60S
POSSIBLE FOR AREAS BORDERING THE SOUTHERN/EASTERN MIDLANDS AND THE
SANTEE RIVER.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST/DPB




000
FXUS62 KCHS 251957
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
357 PM EDT SAT APR 25 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTH THROUGH THE AREA SUNDAY EVENING INTO
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A RATHER SIGNIFICANT NULL IN CONVECTION IS IN PROGRESS ACROSS THE
REGION LATE THIS AFTERNOON AS WEAK SUBSIDENCE HAS OVERSPREAD THE
AREA IN THE WAKE OF A WEAK MID-LEVEL DISTURBANCE. SATELLITE SHOWS
SOME SIGNIFICANT BREAKS IN THE CLOUD CANOPY OVER GEORGIA WHICH IS
HELPING TO PUSH TEMPERATURES BACK INTO THE UPPER 70S TO LOWER 80S
ACROSS SOUTHEAST GEORGIA WITH MID 80S ALONG THE ALTAMAHA RIVER.
THE ATMOSPHERE ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA WILL CONTINUE TO DESTABILIZE OVER THE NEXT FEW HOURS AS
POCKETS OF FOCUSED INSOLATION HELP TO DRIVE TEMPERATURES UP AS
DEWPOINTS RISE INTO THE LOWER 70S. MODIFIED RAP/H3R POINT
SOUNDINGS SUPPORT SBCAPES NEAR 2000 J/KG WITH LIFTED INDICES AS
LOW AS -4 TO -5C AND SHOWALTER INDICES -2 TO -3C--MODERATE VALUES
FOR LATE APRIL. LOW-LEVEL CONVERGENCE IS PROGGED TO INCREASE
ACROSS CENTRAL GEORGIA OVER THE NEXT FEW HOURS AS UPPER FORCING
ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE UPPER JET
OVERSPREAD THE DEEP SOUTH. KMXX/KJGX RADAR TRENDS ALREADY SHOW A
RECENT INCREASE IN SHOWER/TSTM ACTIVITY ALONG THE ALABAMA/GEORGIA
LINE...WHICH SUGGESTS THE FORCING WITH THE UPPER JET IS FINALLY
BEGINNING TO CATCH UP TO THE RIBBON OF HIGHER INSTABILITY THAT IS
BEGINNING TO EXPAND OVER SOUTHERN GEORGIA INTO FAR SOUTHERN SOUTH
CAROLINA.

THE MAIN QUESTION FOR THE EVENING HOURS IS HOW FOCUSED WITH ANY
RISK FOR SEVERE WEATHER BE. HIGH RESOLUTION MODELS...INCLUDING THE
H3R...HAVE BEEN INDICATING SOME SORT OF QLCS MOVING ACROSS
SOUTHEAST GEORGIA AND POSSIBLY AS FAR NORTH AS BEAUFORT OVER THE
NEXT SEVERAL HOURS AS THE CORRIDOR OF JET ENHANCED UPPER FORCING
TRAVERSES THE AREA. 0-6KM BULK SHEAR OF 55-65 KT IS CERTAINLY
SUPPORTIVE OF CONVECTIVE ORGANIZATION WITH POSSIBLE SUPERCELLS...
BUT THE EVENTUAL DEGREE OF INSTABILITY AND DEEP LAYERED FORCING
WILL BE ULTIMATE DETERMINING FACTORS ON HOW CONCENTRATED THE
SEVERE THREAT WILL BECOME. GIVEN THE CONSISTENT TRENDS NOTED IN
THE HIGH RESOLUTION MODELS ALL DAY...ITS HARD TO IGNORE THE
QLCS/BOW ECHO SIGNAL NOTED IN THE MODEL REFLECTIVITY PROGS.
CONVECTIVE TRENDS CONTINUE TO BE MONITORED AND A SEVERE TSTM OR
TORNADO WATCH MAY EVENTUALLY BE NEEDED FOR PARTS OF THE FORECAST
AREA OVER THE NEXT FEW HOURS.

THE PRIMARY HAZARDS LOOK TO BE DAMAGING WINDS...BUT ISOLATED
TORNADOES CAN NOT BE RULED OUT GIVEN THE DEGREE OF 0-1KM SR-
HELICITY IN PLACE. THE RISK FOR SEVERE WEATHER LOOKS TO BE THE
HIGHEST ROUGHLY ALONG/SOUTH OF A METTER-SPRINGFIELD-BEAUFORT
LINE...INCLUDING THE SAVANNAH METRO AREA. THE SEVERE PROBABILITIES
DROP OFF QUITE A BIT NORTH OF THIS LINE...INCLUDING THE
CHARLESTON TRI-COUNTY AREA.

WILL CARRY CHANCE TO LIKELY POPS ACROSS THE AREA THIS EVENING...
HIGHEST SOUTH OF THE I-16 CORRIDOR. WILL REFRAIN FROM INCLUDING
SEVERE WEATHER ATTRIBUTES IN THE GRIDDED AND TEXT FORECASTS FOR
NOW UNTIL CONVECTIVE TRENDS BECOME A BIT MORE APPARENT. ONCE THE
QLCS EXITS THE COAST...MAINLY DRY CONDITIONS WILL PREVAIL WITH
CLEARING SKIES. THE BOUNDARY LAYER LOOKS TO REMAIN COUPLED THROUGH
THE NIGHT WITH MODEST LOW-LEVEL JETTING REMAINING IN PLACE. THE
RISK FOR FOG LOOKS LOW AS A RESULT...BUT SOME AREAS OF LOW STRATUS
COULD DEVELOP JUST BEFORE SUNRISE...ESPECIALLY IN SOUTHEAST
GEORGIA. LOWS WILL ONLY DROP INTO THE UPPER 60S WITH A FEW MID 60S
POSSIBLE FOR AREAS BORDERING THE SOUTHERN/EASTERN MIDLANDS AND THE
SANTEE RIVER.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
SUNDAY...LOW PRESSURE WILL SHIFT OFF THE MID ATLANTIC COAST
EARLY...ALLOWING A BACKDOOR COLD FRONT TO APPROACH THE SOUTHEAST
DURING THE DAY. DEEP WESTERLY FLOW AHEAD OF THE FRONT WILL ALLOW
FAIRLY SIGNIFICANT HEATING OVER THE AREA...WITH AFTERNOON TEMPS
EXPECTED TO PEAK IN THE UPPER 80S TO AROUND 90 DEGREES. GIVEN THIS
AMOUNT OF HEATING...LOW LVL MIXING WILL BE ENHANCED AND WILL LIKELY
RESULT IN BREEZY CONDITIONS THROUGHOUT THE AFTERNOON AS A 30-40 KT
LOW LVL JET PASSES OVER THE SOUTHEASTERN UNITED STATES. AS THE FRONT
BEGINS TO ENTER NORTHERN AREAS DURING THE EVENING...IT WILL BE
SOMEWHAT MOISTURE STARVED. HOWEVER...WE COULD SEE A FEW SHOWERS
AND/OR THUNDERSTORM DURING LATE AFTERNOON INTO EARLY OVERNIGHT HOURS
AS THE FRONT CONTINUES A SOUTHWARD SHIFT OVER THE AREA. SFC WINDS
WILL QUICKLY BECOME NORTH BEHIND THE FRONT...WITH RAPIDLY COOLING
AND DRYING CONDITIONS FROM NORTH TO SOUTH SUNDAY NIGHT. IN
GENERAL...LOW TEMPS WILL RANGE IN THE MID 50S NORTH TO LOW 60S
SOUTH.

MONDAY AND TUESDAY...DRY HIGH PRESSURE WILL BUILD FROM THE
NORTH/NORTHWEST BEHIND A COLD FRONT WELL TO OUR SOUTH. AS A
RESULT...TEMPS WILL BE MUCH COOLER WITHIN NORTHERLY FLOW. IN
GENERAL...MONDAY AFTERNOON HIGHS WILL RANGE FROM THE LOW TO MID
70S...THEN COOL A FEW MORE DEGREES ON TUESDAY AS HIGH PRESSURE
BECOMES CENTERED OVER THE SOUTHEAST. BY TUESDAY EVENING...MOISTURE
RETURNS AS ONSHORE FLOW DEVELOPS WELL AHEAD OF LOW PRESSURE SHIFTING
OVER THE NORTHERN GULF OF MEXICO. A FEW SHOWERS WILL BE
POSSIBLE...MAINLY SOUTH OF INTERSTATE 16 BEFORE SUNSET.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS OF 25
TO POSSIBLY 30 KTS. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUESDAY
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO WEDNESDAY
NIGHT.

&&

.MARINE...
TONIGHT...GUSTY WINDS NEAR 40 KT BRIEFLY OCCURRED EARLIER ACROSS
THE SOUTHERN SOUTH CAROLINA WATERS IN RESPONSE TO MESOSCALE
INFLUENCES FROM A WAKE LOW. THIS FEATURE IS NOW WELL OFFSHORE AND
CONDITIONS WILL SUBSIDE A BIT. MODEST SOUTH/SOUTHWEST WINDS WILL
PERSIST OVERNIGHT WITH SPEEDS 15-20 KT NEARSHORE WATERS AND 20-25
KT OFFSHORE WATERS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
THE GEORGIA OFFSHORE LEG THROUGH THE NIGHT. SEAS WILL AVERAGE 2-4
FT NEARSHORE WATERS AND 4-6 FT OFFSHORE WATERS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
ON SUNDAY AHEAD OF A BACKDOOR COLD FRONT THAT PUSHES SOUTH THROUGH
THE WATERS EARLY SUNDAY NIGHT. WE COULD SEE A BRIEF PERIOD OF SMALL
CRAFT ADVISORY LEVEL CONDITIONS IN THE CHS HARBOR SUNDAY AFTERNOON
AS STRONG HEATING OVER LAND PROMOTES MIXING OF A 30-40 KT LOW LVL
JET TO SFC. BEHIND THE COLD FRONT...A NORTHERLY SURGE WILL ENSUE
WITH CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM SUNDAY
NIGHT. HIGH PRESSURE WILL THEN CONTINUE BUILDING FROM THE NORTH ON
MONDAY...THEN BECOME CENTERED OVER THE AREA ON TUESDAY...LEADING TO
A WEAKENING PRESSURE GRADIENT THROUGH THE PERIOD AND IMPROVED
WINDS/SEAS. CONDITIONS SHOULD THEN GO BACK DOWNHILL AS DEVELOPING
LOW PRESSURE APPROACHES FROM THE SOUTHWEST WEDNESDAY AND PASSES
THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL CRAFT ADVISORIES
POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS BEYOND 20 NM FROM
SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH REGARDING THE
STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST CONFIDENCE IS LOW
AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST/DPB




000
FXUS62 KCAE 251950
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
350 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD INTO THE
AREA. CURRENTLY THE AREA IS BETWEEN WEATHER SYSTEMS...WITH ONE
AREA OF RAINFALL MOVING OFF THE COAST...AND ANOTHER SYSTEM MOVING
ALONG THE GULF OF MEXICO COAST NEAR SOUTHEASTERN LA. ACROSS OUR
REGION...MODELS STILL HINTING AT THE POSSIBILITY OF ADDITIONAL
DEVELOPMENT BACK ACROSS SOUTH-CENTRAL GA LATER THIS AFTERNOON AS
THE GULF SYSTEM MOVES EASTWARD. THE STRONGEST AREA OF SHOWERS AND
STORMS MAY REMAIN JUST SOUTH OF THE MAJORITY OF THE FORECAST AREA
BASED OFF THE LATEST HRRR. EVEN SO...STILL CANNOT RULE OUT SEEING
SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING PROGRESSES.
INSTABILITY SHOULD INCREASE WITH SOME BREAKS IN THE CLOUDS. SHEAR
VALUES REMAIN HIGH THROUGH THE AFTERNOON AND EVENING...WHICH WOULD
HELP SUPPORT ROTATING STORMS IF ANY CAN PUSH INTO THE AREA. SPC
CONTINUES TO SHOW OUR ENTIRE AREA IN A SLIGHT RISK...WITH AN AREA
OF ENHANCED RISK ACROSS TN/KY.

FOR TONIGHT...MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE
GULF SYSTEM MOVES SOUTH OF THE AREA. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
RAIN HAS CONTINUED TO MOVE EAST AND IS NOW OFF OF THE COAST. SHOWERS
ARE NOT EXPECTED TO MOVE BACK INTO THE AREA UNTIL LATE THIS
AFTERNOON INTO THE EVENING. IFR CONDITIONS EXIST UPSTREAM AND WILL
CONTINUE TO FEED WESTWARD. THESE IFR/MVFR CEILINGS SHOULD REMAIN
THROUGH THE AFTERNOON AND OVERNIGHT.

MODELS TEND TO KEEP SHOWER ACTIVITY THIS EVENING TO THE
SOUTH...POSSIBLY SKIRTING ALONG THE CSRA. HOWEVER CONFIDENCE IS LOW
THAT ADDITIONAL RAINFALL WILL OCCUR. IF CONVECTION FORMS IN CENTRAL
GA IT MAY ROB THE MOISTURE NECESSARY FOR SHOWERS IN OUR AREA.

SOUTHEAST TO SOUTHERLY WINDS ARE EXPECTED THIS AFTERNOON UNTIL
THE WARM FRONT LIFTS THROUGH AND THEN WINDS BECOME MORE SOUTHWESTERLY
THIS EVENING. LOW-LEVEL WIND SHEAR MAY CONTINUE TO BE AN ISSUE AS
A STRONG JET STRENGTHENS OVERNIGHT. WESTERLY WINDS AND DOWNSLOPE
FLOW SUNDAY WILL BEGIN TO SCOUR OUT OVERCAST SKIES.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KCAE 251950
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
350 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD INTO THE
AREA. CURRENTLY THE AREA IS BETWEEN WEATHER SYSTEMS...WITH ONE
AREA OF RAINFALL MOVING OFF THE COAST...AND ANOTHER SYSTEM MOVING
ALONG THE GULF OF MEXICO COAST NEAR SOUTHEASTERN LA. ACROSS OUR
REGION...MODELS STILL HINTING AT THE POSSIBILITY OF ADDITIONAL
DEVELOPMENT BACK ACROSS SOUTH-CENTRAL GA LATER THIS AFTERNOON AS
THE GULF SYSTEM MOVES EASTWARD. THE STRONGEST AREA OF SHOWERS AND
STORMS MAY REMAIN JUST SOUTH OF THE MAJORITY OF THE FORECAST AREA
BASED OFF THE LATEST HRRR. EVEN SO...STILL CANNOT RULE OUT SEEING
SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING PROGRESSES.
INSTABILITY SHOULD INCREASE WITH SOME BREAKS IN THE CLOUDS. SHEAR
VALUES REMAIN HIGH THROUGH THE AFTERNOON AND EVENING...WHICH WOULD
HELP SUPPORT ROTATING STORMS IF ANY CAN PUSH INTO THE AREA. SPC
CONTINUES TO SHOW OUR ENTIRE AREA IN A SLIGHT RISK...WITH AN AREA
OF ENHANCED RISK ACROSS TN/KY.

FOR TONIGHT...MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE
GULF SYSTEM MOVES SOUTH OF THE AREA. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
RAIN HAS CONTINUED TO MOVE EAST AND IS NOW OFF OF THE COAST. SHOWERS
ARE NOT EXPECTED TO MOVE BACK INTO THE AREA UNTIL LATE THIS
AFTERNOON INTO THE EVENING. IFR CONDITIONS EXIST UPSTREAM AND WILL
CONTINUE TO FEED WESTWARD. THESE IFR/MVFR CEILINGS SHOULD REMAIN
THROUGH THE AFTERNOON AND OVERNIGHT.

MODELS TEND TO KEEP SHOWER ACTIVITY THIS EVENING TO THE
SOUTH...POSSIBLY SKIRTING ALONG THE CSRA. HOWEVER CONFIDENCE IS LOW
THAT ADDITIONAL RAINFALL WILL OCCUR. IF CONVECTION FORMS IN CENTRAL
GA IT MAY ROB THE MOISTURE NECESSARY FOR SHOWERS IN OUR AREA.

SOUTHEAST TO SOUTHERLY WINDS ARE EXPECTED THIS AFTERNOON UNTIL
THE WARM FRONT LIFTS THROUGH AND THEN WINDS BECOME MORE SOUTHWESTERLY
THIS EVENING. LOW-LEVEL WIND SHEAR MAY CONTINUE TO BE AN ISSUE AS
A STRONG JET STRENGTHENS OVERNIGHT. WESTERLY WINDS AND DOWNSLOPE
FLOW SUNDAY WILL BEGIN TO SCOUR OUT OVERCAST SKIES.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KCAE 251950
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
350 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD INTO THE
AREA. CURRENTLY THE AREA IS BETWEEN WEATHER SYSTEMS...WITH ONE
AREA OF RAINFALL MOVING OFF THE COAST...AND ANOTHER SYSTEM MOVING
ALONG THE GULF OF MEXICO COAST NEAR SOUTHEASTERN LA. ACROSS OUR
REGION...MODELS STILL HINTING AT THE POSSIBILITY OF ADDITIONAL
DEVELOPMENT BACK ACROSS SOUTH-CENTRAL GA LATER THIS AFTERNOON AS
THE GULF SYSTEM MOVES EASTWARD. THE STRONGEST AREA OF SHOWERS AND
STORMS MAY REMAIN JUST SOUTH OF THE MAJORITY OF THE FORECAST AREA
BASED OFF THE LATEST HRRR. EVEN SO...STILL CANNOT RULE OUT SEEING
SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING PROGRESSES.
INSTABILITY SHOULD INCREASE WITH SOME BREAKS IN THE CLOUDS. SHEAR
VALUES REMAIN HIGH THROUGH THE AFTERNOON AND EVENING...WHICH WOULD
HELP SUPPORT ROTATING STORMS IF ANY CAN PUSH INTO THE AREA. SPC
CONTINUES TO SHOW OUR ENTIRE AREA IN A SLIGHT RISK...WITH AN AREA
OF ENHANCED RISK ACROSS TN/KY.

FOR TONIGHT...MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE
GULF SYSTEM MOVES SOUTH OF THE AREA. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
RAIN HAS CONTINUED TO MOVE EAST AND IS NOW OFF OF THE COAST. SHOWERS
ARE NOT EXPECTED TO MOVE BACK INTO THE AREA UNTIL LATE THIS
AFTERNOON INTO THE EVENING. IFR CONDITIONS EXIST UPSTREAM AND WILL
CONTINUE TO FEED WESTWARD. THESE IFR/MVFR CEILINGS SHOULD REMAIN
THROUGH THE AFTERNOON AND OVERNIGHT.

MODELS TEND TO KEEP SHOWER ACTIVITY THIS EVENING TO THE
SOUTH...POSSIBLY SKIRTING ALONG THE CSRA. HOWEVER CONFIDENCE IS LOW
THAT ADDITIONAL RAINFALL WILL OCCUR. IF CONVECTION FORMS IN CENTRAL
GA IT MAY ROB THE MOISTURE NECESSARY FOR SHOWERS IN OUR AREA.

SOUTHEAST TO SOUTHERLY WINDS ARE EXPECTED THIS AFTERNOON UNTIL
THE WARM FRONT LIFTS THROUGH AND THEN WINDS BECOME MORE SOUTHWESTERLY
THIS EVENING. LOW-LEVEL WIND SHEAR MAY CONTINUE TO BE AN ISSUE AS
A STRONG JET STRENGTHENS OVERNIGHT. WESTERLY WINDS AND DOWNSLOPE
FLOW SUNDAY WILL BEGIN TO SCOUR OUT OVERCAST SKIES.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KCAE 251950
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
350 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD INTO THE
AREA. CURRENTLY THE AREA IS BETWEEN WEATHER SYSTEMS...WITH ONE
AREA OF RAINFALL MOVING OFF THE COAST...AND ANOTHER SYSTEM MOVING
ALONG THE GULF OF MEXICO COAST NEAR SOUTHEASTERN LA. ACROSS OUR
REGION...MODELS STILL HINTING AT THE POSSIBILITY OF ADDITIONAL
DEVELOPMENT BACK ACROSS SOUTH-CENTRAL GA LATER THIS AFTERNOON AS
THE GULF SYSTEM MOVES EASTWARD. THE STRONGEST AREA OF SHOWERS AND
STORMS MAY REMAIN JUST SOUTH OF THE MAJORITY OF THE FORECAST AREA
BASED OFF THE LATEST HRRR. EVEN SO...STILL CANNOT RULE OUT SEEING
SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING PROGRESSES.
INSTABILITY SHOULD INCREASE WITH SOME BREAKS IN THE CLOUDS. SHEAR
VALUES REMAIN HIGH THROUGH THE AFTERNOON AND EVENING...WHICH WOULD
HELP SUPPORT ROTATING STORMS IF ANY CAN PUSH INTO THE AREA. SPC
CONTINUES TO SHOW OUR ENTIRE AREA IN A SLIGHT RISK...WITH AN AREA
OF ENHANCED RISK ACROSS TN/KY.

FOR TONIGHT...MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE
GULF SYSTEM MOVES SOUTH OF THE AREA. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500 MB TEMPS NOTED ON
SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO
WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM-RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT OR
JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
RAIN HAS CONTINUED TO MOVE EAST AND IS NOW OFF OF THE COAST. SHOWERS
ARE NOT EXPECTED TO MOVE BACK INTO THE AREA UNTIL LATE THIS
AFTERNOON INTO THE EVENING. IFR CONDITIONS EXIST UPSTREAM AND WILL
CONTINUE TO FEED WESTWARD. THESE IFR/MVFR CEILINGS SHOULD REMAIN
THROUGH THE AFTERNOON AND OVERNIGHT.

MODELS TEND TO KEEP SHOWER ACTIVITY THIS EVENING TO THE
SOUTH...POSSIBLY SKIRTING ALONG THE CSRA. HOWEVER CONFIDENCE IS LOW
THAT ADDITIONAL RAINFALL WILL OCCUR. IF CONVECTION FORMS IN CENTRAL
GA IT MAY ROB THE MOISTURE NECESSARY FOR SHOWERS IN OUR AREA.

SOUTHEAST TO SOUTHERLY WINDS ARE EXPECTED THIS AFTERNOON UNTIL
THE WARM FRONT LIFTS THROUGH AND THEN WINDS BECOME MORE SOUTHWESTERLY
THIS EVENING. LOW-LEVEL WIND SHEAR MAY CONTINUE TO BE AN ISSUE AS
A STRONG JET STRENGTHENS OVERNIGHT. WESTERLY WINDS AND DOWNSLOPE
FLOW SUNDAY WILL BEGIN TO SCOUR OUT OVERCAST SKIES.

EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED MONDAY
AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN WIDESPREAD
RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KGSP 251825
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
225 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
AT KCLT...LOW CONFIDENCE FORECAST...WITH MODEL GUIDANCE QUITE
DIVERGENT. OBSERVATIONS SHOW IFR CIG RESTRICTION...BUT VSBY HAS
IMPROVED BEHIND DEPARTING RAINFALL. MODEL TIME HEIGHTS SUPPORT BRIEF
CIG IMPROVEMENT TO LOW VFR THIS EVENING BEFORE LOWERING TO AT LEAST
MVFR LATE TONIGHT INTO SUNDAY MORNING. GUIDANCE SUPPORTS AN MVFR
VSBY LATE THIS EVENING...BUT SUGGEST A RETURN TO VFR TOWARD DAWN...
OSTENSIBLY DUE TO NE WINDS THAT SET UP OVERNIGHT AS A COLD FRONT
ARRIVES FROM THE N. CONVECTIVE CHANCES APPEAR BEST OVERNIGHT AS THE
FRONT APPROACHES.

ELSEWHERE...CONFIDENCE IS LIMITED AS TRENDS DEPART FORM PREVIOUS
FORECAST...AND MODEL SOLUTIONS DIVERGE. OBSERVED CIG RESTRICTIONS
MAY IMPROVE THIS EVENING BASED ON MODEL TIME HEIGHTS...BUT PROBABLY
NOT AS MUCH AS A MODEL BLEND WOULD SUGGEST. VSBY IMPROVEMENT HAS
BEEN NOTED AS RAINFALL MOVES OFF TO THE EAST...AND THIS TREND IS
EXPECTED OT CONTINUE. TIME HEIGHTS SHOW CIGS LOWERING AGAIN TOWARD
DAWN...AND REMAINING LOW INTO SUNDAY MORNING. VSBY RESTRICTIONS
APPEAR TO RETURN AT KHKY LATE THIS EVENING...THEN END AS A BACK DOOR
COLD FRONT ARRIVES BEFORE DAWN VEERING THE WIND TO THE NE. MODEL
DATA SUPPORTS KAND HAVING A DAYBREAK VSBY RESTRICTION...BUT MODEL
WINDS REMAIN UP...FAVORING VFR. CONVECTIVE CHANCES NOW APPEAR TO BE
BEST OVERNIGHT AHEAD OF THE COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       HIGH  97%     LOW   54%     MED   61%     MED   76%
KGSP       HIGH  83%     HIGH  90%     MED   67%     MED   60%
KAVL       MED   72%     MED   64%     LOW   57%     MED   75%
KHKY       HIGH  97%     LOW   55%     MED   68%     HIGH  85%
KGMU       HIGH  82%     HIGH  86%     MED   66%     MED   60%
KAND       HIGH  84%     HIGH  98%     MED   67%     MED   62%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...JAT




000
FXUS62 KGSP 251825
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
225 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
AT KCLT...LOW CONFIDENCE FORECAST...WITH MODEL GUIDANCE QUITE
DIVERGENT. OBSERVATIONS SHOW IFR CIG RESTRICTION...BUT VSBY HAS
IMPROVED BEHIND DEPARTING RAINFALL. MODEL TIME HEIGHTS SUPPORT BRIEF
CIG IMPROVEMENT TO LOW VFR THIS EVENING BEFORE LOWERING TO AT LEAST
MVFR LATE TONIGHT INTO SUNDAY MORNING. GUIDANCE SUPPORTS AN MVFR
VSBY LATE THIS EVENING...BUT SUGGEST A RETURN TO VFR TOWARD DAWN...
OSTENSIBLY DUE TO NE WINDS THAT SET UP OVERNIGHT AS A COLD FRONT
ARRIVES FROM THE N. CONVECTIVE CHANCES APPEAR BEST OVERNIGHT AS THE
FRONT APPROACHES.

ELSEWHERE...CONFIDENCE IS LIMITED AS TRENDS DEPART FORM PREVIOUS
FORECAST...AND MODEL SOLUTIONS DIVERGE. OBSERVED CIG RESTRICTIONS
MAY IMPROVE THIS EVENING BASED ON MODEL TIME HEIGHTS...BUT PROBABLY
NOT AS MUCH AS A MODEL BLEND WOULD SUGGEST. VSBY IMPROVEMENT HAS
BEEN NOTED AS RAINFALL MOVES OFF TO THE EAST...AND THIS TREND IS
EXPECTED OT CONTINUE. TIME HEIGHTS SHOW CIGS LOWERING AGAIN TOWARD
DAWN...AND REMAINING LOW INTO SUNDAY MORNING. VSBY RESTRICTIONS
APPEAR TO RETURN AT KHKY LATE THIS EVENING...THEN END AS A BACK DOOR
COLD FRONT ARRIVES BEFORE DAWN VEERING THE WIND TO THE NE. MODEL
DATA SUPPORTS KAND HAVING A DAYBREAK VSBY RESTRICTION...BUT MODEL
WINDS REMAIN UP...FAVORING VFR. CONVECTIVE CHANCES NOW APPEAR TO BE
BEST OVERNIGHT AHEAD OF THE COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       HIGH  97%     LOW   54%     MED   61%     MED   76%
KGSP       HIGH  83%     HIGH  90%     MED   67%     MED   60%
KAVL       MED   72%     MED   64%     LOW   57%     MED   75%
KHKY       HIGH  97%     LOW   55%     MED   68%     HIGH  85%
KGMU       HIGH  82%     HIGH  86%     MED   66%     MED   60%
KAND       HIGH  84%     HIGH  98%     MED   67%     MED   62%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...JAT




000
FXUS62 KGSP 251825
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
225 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
AT KCLT...LOW CONFIDENCE FORECAST...WITH MODEL GUIDANCE QUITE
DIVERGENT. OBSERVATIONS SHOW IFR CIG RESTRICTION...BUT VSBY HAS
IMPROVED BEHIND DEPARTING RAINFALL. MODEL TIME HEIGHTS SUPPORT BRIEF
CIG IMPROVEMENT TO LOW VFR THIS EVENING BEFORE LOWERING TO AT LEAST
MVFR LATE TONIGHT INTO SUNDAY MORNING. GUIDANCE SUPPORTS AN MVFR
VSBY LATE THIS EVENING...BUT SUGGEST A RETURN TO VFR TOWARD DAWN...
OSTENSIBLY DUE TO NE WINDS THAT SET UP OVERNIGHT AS A COLD FRONT
ARRIVES FROM THE N. CONVECTIVE CHANCES APPEAR BEST OVERNIGHT AS THE
FRONT APPROACHES.

ELSEWHERE...CONFIDENCE IS LIMITED AS TRENDS DEPART FORM PREVIOUS
FORECAST...AND MODEL SOLUTIONS DIVERGE. OBSERVED CIG RESTRICTIONS
MAY IMPROVE THIS EVENING BASED ON MODEL TIME HEIGHTS...BUT PROBABLY
NOT AS MUCH AS A MODEL BLEND WOULD SUGGEST. VSBY IMPROVEMENT HAS
BEEN NOTED AS RAINFALL MOVES OFF TO THE EAST...AND THIS TREND IS
EXPECTED OT CONTINUE. TIME HEIGHTS SHOW CIGS LOWERING AGAIN TOWARD
DAWN...AND REMAINING LOW INTO SUNDAY MORNING. VSBY RESTRICTIONS
APPEAR TO RETURN AT KHKY LATE THIS EVENING...THEN END AS A BACK DOOR
COLD FRONT ARRIVES BEFORE DAWN VEERING THE WIND TO THE NE. MODEL
DATA SUPPORTS KAND HAVING A DAYBREAK VSBY RESTRICTION...BUT MODEL
WINDS REMAIN UP...FAVORING VFR. CONVECTIVE CHANCES NOW APPEAR TO BE
BEST OVERNIGHT AHEAD OF THE COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       HIGH  97%     LOW   54%     MED   61%     MED   76%
KGSP       HIGH  83%     HIGH  90%     MED   67%     MED   60%
KAVL       MED   72%     MED   64%     LOW   57%     MED   75%
KHKY       HIGH  97%     LOW   55%     MED   68%     HIGH  85%
KGMU       HIGH  82%     HIGH  86%     MED   66%     MED   60%
KAND       HIGH  84%     HIGH  98%     MED   67%     MED   62%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...JAT



000
FXUS62 KGSP 251825
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
225 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
AT 230 PM EDT SATURDAY...A LOW AMPLITUDE UPPER TROUGH WAS LOCATED
OVER THE SOUTHERN APPALACHIANS THIS AFTERNOON...WHILE A CLOSED LOW
WAS OVER THE MID MS RIVER VALLEY.  THE TROUGH IS EXPECTED TO
DEAMPLIFY THIS EVENING WHILE THE CLOSED UP FILLS...RESULTING IN
ZONAL FOR OVER THE SE. SHORTWAVES MOVING THROUGH THIS FLOW WILL
CROSS OUR AREA THIS EVENING...AND AGAIN ON SUNDAY MORNING.

AT THE SURFACE...A STATIONARY FRONT WAS LOCATED FROM THE NORTHERN NC
MOUNTAINS TO THE NC OUTER BANKS EARLY THIS AFTERNOON. ALTHOUGH MOIST
ISENTROPIC UPGLIDE AND LOW CLOUDS REMAIN OVER MOST OF OUR AREA...THE
BULK OF PRECIPITATION HAS MOVES EAST OF THE AREA WITH A DEPARTING
SHORTWAVE. PRECIPITATION CHANCES ARE EXPECTED TO INCREASE AGAIN THIS
EVENING THE FRONT TO OUR NORTH DROPS SOUTH...EVEN AS UPGLIDE
WEAKENS. INSTABILITY AND SHEAR BOTH INCREASE ABOVE A LOW LEVEL
INCREASE OVERNIGHT...BEFORE A DECREASE TOWARD DAWN...INCREASING
SUPPORT FOR ELEVATED ORGANIZED CONVECTION. MINIMUM TEMPERATURES WILL
RUN ABOVE NORMAL UNDER CLOUD COVER. AS THE COLD FRONT MOVES SOUTH
ACROSS OUR AREA ON SUNDAY...A DRYING DOWNSLOPE FLOW WILL FOLLOW IN
ITS WAKE...RESULTING IN WARMING TEMPERATURES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 210 PM SATURDAY...AS COLD FRONT SAGS SOUTH ACROSS THE AREA...
ISLD/SCT SHOWERS WILL REMAIN POSSIBLE ACROSS SOUTHERN PIEDMONT AREAS
INTO SUNDAY EVENING. MEANWHILE...A RELATIVELY MODEST/MOIST NW FLOW
COULD YIELD SOME SCATTERED SHOWERS NEAR THE TENNESSEE BORDER AS
WELL. POPS WILL GENERALLY BE CONFINED TO THOSE AREAS DURING THE
EVENING HOURS.

THE REMAINDER OF THE SHORT TERM WILL BE PLEASANTLY COOL AND DRY
UNDER THE INFLUENCE OF A BROAD LONG WAVE TROUGH ALONG THE EAST
COAST/WESTERN ATLANTIC...WITH A COUPLE OF PERIODIC SHORT WAVE
TROUGHS ONLY ACTING TO REINFORCE THE BELOW CLIMO TEMPS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM SATURDAY...CHANCES FOR PRECIPITATION WILL GRADUALLY
INCREASE THROUGH MID-WEEK...AS A SOUTHERN STREAM AREA OF LOW
PRESSURE WOBBLES OUT OF THE FOUR CORNERS REGION/TEXAS AND OPENS UP
ACROSS THE SOUTHEAST. THIS WILL CREATE COMPLICATIONS TO THE UPPER
PATTERN IN TERMS OF HOW THE NORTHERN AND SOUTHERN STREAMS WILL
INTERACT (IF AT ALL)...AND INDEED GLOBAL MODEL SOLUTIONS ARE QUITE
DISPARATE REGARDING THE SYNOPTIC DETAILS FOR MID-WEEK...ESP
REGARDING SOUTHEAST COASTAL LOW PRESSURE. NEVERTHELESS...ALL GLOBAL
MODELS AND ENSEMBLE SOLUTIONS DEPICT AT LEAST A WEAK WAVE OF LOW
PRESSURE ACROSS THE NORTHERN GULF BY TUE AFTERNOON...THUS CHANCE
POPS WILL SPREAD INTO THE AREA FROM THE SOUTHWEST TUE NIGHT INTO
WEDNESDAY. UNCERTAINTY REALLY EXPLODES AFTER WED...WHEN
DETERMINISTIC MODEL SOLUTIONS DIVERGE CONSIDERABLY (WITH THE ECMWF
DEVELOPING AN INTENSE/MILLER-A CYCLONE OFF THE CAROLINA COAST BY
THURSDAY...WHILE THE GFS BARELY DEPICTS A WEAK WAVE IN THIS AREA).
NEVERTHELESS...ENSEMBLE GLOBAL ENSEMBLE MEAN SOLUTIONS SUPPORT
MAINTAINING LOW POPS INTO THURSDAY. DRY AND SEASONABLY WARM
CONDITIONS ARE EXPECTED TO RETURN FOR LATE WEEK.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
AT KCLT...LOW CONFIDENCE FORECAST...WITH MODEL GUIDANCE QUITE
DIVERGENT. OBSERVATIONS SHOW IFR CIG RESTRICTION...BUT VSBY HAS
IMPROVED BEHIND DEPARTING RAINFALL. MODEL TIME HEIGHTS SUPPORT BRIEF
CIG IMPROVEMENT TO LOW VFR THIS EVENING BEFORE LOWERING TO AT LEAST
MVFR LATE TONIGHT INTO SUNDAY MORNING. GUIDANCE SUPPORTS AN MVFR
VSBY LATE THIS EVENING...BUT SUGGEST A RETURN TO VFR TOWARD DAWN...
OSTENSIBLY DUE TO NE WINDS THAT SET UP OVERNIGHT AS A COLD FRONT
ARRIVES FROM THE N. CONVECTIVE CHANCES APPEAR BEST OVERNIGHT AS THE
FRONT APPROACHES.

ELSEWHERE...CONFIDENCE IS LIMITED AS TRENDS DEPART FORM PREVIOUS
FORECAST...AND MODEL SOLUTIONS DIVERGE. OBSERVED CIG RESTRICTIONS
MAY IMPROVE THIS EVENING BASED ON MODEL TIME HEIGHTS...BUT PROBABLY
NOT AS MUCH AS A MODEL BLEND WOULD SUGGEST. VSBY IMPROVEMENT HAS
BEEN NOTED AS RAINFALL MOVES OFF TO THE EAST...AND THIS TREND IS
EXPECTED OT CONTINUE. TIME HEIGHTS SHOW CIGS LOWERING AGAIN TOWARD
DAWN...AND REMAINING LOW INTO SUNDAY MORNING. VSBY RESTRICTIONS
APPEAR TO RETURN AT KHKY LATE THIS EVENING...THEN END AS A BACK DOOR
COLD FRONT ARRIVES BEFORE DAWN VEERING THE WIND TO THE NE. MODEL
DATA SUPPORTS KAND HAVING A DAYBREAK VSBY RESTRICTION...BUT MODEL
WINDS REMAIN UP...FAVORING VFR. CONVECTIVE CHANCES NOW APPEAR TO BE
BEST OVERNIGHT AHEAD OF THE COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       HIGH  97%     LOW   54%     MED   61%     MED   76%
KGSP       HIGH  83%     HIGH  90%     MED   67%     MED   60%
KAVL       MED   72%     MED   64%     LOW   57%     MED   75%
KHKY       HIGH  97%     LOW   55%     MED   68%     HIGH  85%
KGMU       HIGH  82%     HIGH  86%     MED   66%     MED   60%
KAND       HIGH  84%     HIGH  98%     MED   67%     MED   62%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...JAT



000
FXUS62 KCAE 251801
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
201 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /THROUGH TONIGHT/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD INTO THE
AREA. CURRENT THE AREA IS BETWEEN WEATHER SYSTEMS...WITH ONE AREA
OF RAINFALL MOVING OFF THE COAST...AND ANOTHER SYSTEM MOVING ALONG
THE GULF OF MEXICO COAST NEAR SOUTHEASTERN LA. ACROSS OUR
REGION...MODELS STILL HINTING AT THE POSSIBILITY OF ADDITIONAL
DEVELOPMENT BACK ACROSS SOUTH-CENTRAL GA LATER THIS AFTERNOON AS
THE GULF SYSTEM MOVES EASTWARD. THE STRONGEST AREA OF SHOWERS AND
STORMS MAY REMAIN JUST SOUTH OF THE MAJORITY OF THE FORECAST AREA
BASED OFF THE LATEST HRRR. EVEN SO...STILL CAN NOT RULE OUT SEEING
SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING PROGRESSES.
INSTABILITY SHOULD INCREASE WITH SOME BREAKS IN THE CLOUDS. SHEAR
VALUES REMAIN HIGH THROUGH THE AFTERNOON AND EVENING...WHICH WOULD
HELP SUPPORT ROTATING STORMS IF ANY CAN PUSH INTO THE AREA. SPC
CONTINUES TO SHOW OUR ENTIRE AREA IN A SLIGHT RISK...WITH AN AREA
OF ENHANCED RISK ACROSS TN/KY.

FOR TONIGHT...MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE
GULF SYSTEM MOVES SOUTH OF THE AREA. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS NOTED ON SUNDAY
BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO WILL
CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT
OR JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...

RAIN HAS CONTINUED TO MOVE EAST AND IS NOW OFF OF THE COAST. SHOWERS
ARE NOT EXPECTED TO MOVE BACK INTO THE AREA UNTIL LATE THIS
AFTERNOON INTO THE EVENING. IFR CONDITIONS EXIST UPSTREAM AND WILL
CONTINUE TO FEED WESTWARD. THESE IFR/MVFR CEILINGS SHOULD REMAIN
THROUGH THE AFTERNOON AND OVERNIGHT.

MODELS TEND TO KEEP SHOWER ACTIVITY THIS EVENING TO THE
SOUTH...POSSIBLY SKIRTING ALONG THE CSRA. HOWEVER CONFIDENCE IS LOW
THAT ADDITIONAL RAINFALL WILL OCCUR. IF CONVECTION FORMS IN CENTRAL
GA IT MAY ROB THE MOISTURE NECESSARY FOR SHOWERS IN OUR AREA.

SOUTHEAST TO SOUTHERLY WINDS ARE EXPECTED TODAY UNTIL THE WARM FRONT
LIFTS THROUGH AND THEN WINDS BECOME MORE SOUTHWESTERLY THIS
EVENING. LOW-LEVEL WIND SHEAR MAY CONTINUE TO BE AN ISSUE AS A
STRONG MID-LEVEL JET STRENGTHENS OVERNIGHT. WESTERLY WINDS AND
DOWNSLOPE FLOW ON SUNDAY WILL BEGIN TO SCOUR OUT OVERCAST SKIES.

EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SUNDAY. NO
SIGNIFICANT IMPACTS EXPECTED MONDAY AND TUESDAY. AN APPROACHING
WARM FRONT MAY RESULT IN WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$















000
FXUS62 KCAE 251801
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
201 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /THROUGH TONIGHT/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD INTO THE
AREA. CURRENT THE AREA IS BETWEEN WEATHER SYSTEMS...WITH ONE AREA
OF RAINFALL MOVING OFF THE COAST...AND ANOTHER SYSTEM MOVING ALONG
THE GULF OF MEXICO COAST NEAR SOUTHEASTERN LA. ACROSS OUR
REGION...MODELS STILL HINTING AT THE POSSIBILITY OF ADDITIONAL
DEVELOPMENT BACK ACROSS SOUTH-CENTRAL GA LATER THIS AFTERNOON AS
THE GULF SYSTEM MOVES EASTWARD. THE STRONGEST AREA OF SHOWERS AND
STORMS MAY REMAIN JUST SOUTH OF THE MAJORITY OF THE FORECAST AREA
BASED OFF THE LATEST HRRR. EVEN SO...STILL CAN NOT RULE OUT SEEING
SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING PROGRESSES.
INSTABILITY SHOULD INCREASE WITH SOME BREAKS IN THE CLOUDS. SHEAR
VALUES REMAIN HIGH THROUGH THE AFTERNOON AND EVENING...WHICH WOULD
HELP SUPPORT ROTATING STORMS IF ANY CAN PUSH INTO THE AREA. SPC
CONTINUES TO SHOW OUR ENTIRE AREA IN A SLIGHT RISK...WITH AN AREA
OF ENHANCED RISK ACROSS TN/KY.

FOR TONIGHT...MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE
GULF SYSTEM MOVES SOUTH OF THE AREA. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS NOTED ON SUNDAY
BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO WILL
CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT
OR JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...

RAIN HAS CONTINUED TO MOVE EAST AND IS NOW OFF OF THE COAST. SHOWERS
ARE NOT EXPECTED TO MOVE BACK INTO THE AREA UNTIL LATE THIS
AFTERNOON INTO THE EVENING. IFR CONDITIONS EXIST UPSTREAM AND WILL
CONTINUE TO FEED WESTWARD. THESE IFR/MVFR CEILINGS SHOULD REMAIN
THROUGH THE AFTERNOON AND OVERNIGHT.

MODELS TEND TO KEEP SHOWER ACTIVITY THIS EVENING TO THE
SOUTH...POSSIBLY SKIRTING ALONG THE CSRA. HOWEVER CONFIDENCE IS LOW
THAT ADDITIONAL RAINFALL WILL OCCUR. IF CONVECTION FORMS IN CENTRAL
GA IT MAY ROB THE MOISTURE NECESSARY FOR SHOWERS IN OUR AREA.

SOUTHEAST TO SOUTHERLY WINDS ARE EXPECTED TODAY UNTIL THE WARM FRONT
LIFTS THROUGH AND THEN WINDS BECOME MORE SOUTHWESTERLY THIS
EVENING. LOW-LEVEL WIND SHEAR MAY CONTINUE TO BE AN ISSUE AS A
STRONG MID-LEVEL JET STRENGTHENS OVERNIGHT. WESTERLY WINDS AND
DOWNSLOPE FLOW ON SUNDAY WILL BEGIN TO SCOUR OUT OVERCAST SKIES.

EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SUNDAY. NO
SIGNIFICANT IMPACTS EXPECTED MONDAY AND TUESDAY. AN APPROACHING
WARM FRONT MAY RESULT IN WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$
















000
FXUS62 KCAE 251801
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
201 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /THROUGH TONIGHT/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD INTO THE
AREA. CURRENT THE AREA IS BETWEEN WEATHER SYSTEMS...WITH ONE AREA
OF RAINFALL MOVING OFF THE COAST...AND ANOTHER SYSTEM MOVING ALONG
THE GULF OF MEXICO COAST NEAR SOUTHEASTERN LA. ACROSS OUR
REGION...MODELS STILL HINTING AT THE POSSIBILITY OF ADDITIONAL
DEVELOPMENT BACK ACROSS SOUTH-CENTRAL GA LATER THIS AFTERNOON AS
THE GULF SYSTEM MOVES EASTWARD. THE STRONGEST AREA OF SHOWERS AND
STORMS MAY REMAIN JUST SOUTH OF THE MAJORITY OF THE FORECAST AREA
BASED OFF THE LATEST HRRR. EVEN SO...STILL CAN NOT RULE OUT SEEING
SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING PROGRESSES.
INSTABILITY SHOULD INCREASE WITH SOME BREAKS IN THE CLOUDS. SHEAR
VALUES REMAIN HIGH THROUGH THE AFTERNOON AND EVENING...WHICH WOULD
HELP SUPPORT ROTATING STORMS IF ANY CAN PUSH INTO THE AREA. SPC
CONTINUES TO SHOW OUR ENTIRE AREA IN A SLIGHT RISK...WITH AN AREA
OF ENHANCED RISK ACROSS TN/KY.

FOR TONIGHT...MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE
GULF SYSTEM MOVES SOUTH OF THE AREA. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS NOTED ON SUNDAY
BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO WILL
CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT
OR JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...

RAIN HAS CONTINUED TO MOVE EAST AND IS NOW OFF OF THE COAST. SHOWERS
ARE NOT EXPECTED TO MOVE BACK INTO THE AREA UNTIL LATE THIS
AFTERNOON INTO THE EVENING. IFR CONDITIONS EXIST UPSTREAM AND WILL
CONTINUE TO FEED WESTWARD. THESE IFR/MVFR CEILINGS SHOULD REMAIN
THROUGH THE AFTERNOON AND OVERNIGHT.

MODELS TEND TO KEEP SHOWER ACTIVITY THIS EVENING TO THE
SOUTH...POSSIBLY SKIRTING ALONG THE CSRA. HOWEVER CONFIDENCE IS LOW
THAT ADDITIONAL RAINFALL WILL OCCUR. IF CONVECTION FORMS IN CENTRAL
GA IT MAY ROB THE MOISTURE NECESSARY FOR SHOWERS IN OUR AREA.

SOUTHEAST TO SOUTHERLY WINDS ARE EXPECTED TODAY UNTIL THE WARM FRONT
LIFTS THROUGH AND THEN WINDS BECOME MORE SOUTHWESTERLY THIS
EVENING. LOW-LEVEL WIND SHEAR MAY CONTINUE TO BE AN ISSUE AS A
STRONG MID-LEVEL JET STRENGTHENS OVERNIGHT. WESTERLY WINDS AND
DOWNSLOPE FLOW ON SUNDAY WILL BEGIN TO SCOUR OUT OVERCAST SKIES.

EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SUNDAY. NO
SIGNIFICANT IMPACTS EXPECTED MONDAY AND TUESDAY. AN APPROACHING
WARM FRONT MAY RESULT IN WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$















000
FXUS62 KCAE 251801
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
201 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT ACROSS THE REGION WILL BE THE FOCUS FOR SHOWERS AND
SOME THUNDERSTORMS TONIGHT. DRIER WEATHER RETURNS FOR SUNDAY AS A
COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /THROUGH TONIGHT/...
A WARM FRONT WILL CONTINUE TO SLOWLY LIFT NORTHWARD INTO THE
AREA. CURRENT THE AREA IS BETWEEN WEATHER SYSTEMS...WITH ONE AREA
OF RAINFALL MOVING OFF THE COAST...AND ANOTHER SYSTEM MOVING ALONG
THE GULF OF MEXICO COAST NEAR SOUTHEASTERN LA. ACROSS OUR
REGION...MODELS STILL HINTING AT THE POSSIBILITY OF ADDITIONAL
DEVELOPMENT BACK ACROSS SOUTH-CENTRAL GA LATER THIS AFTERNOON AS
THE GULF SYSTEM MOVES EASTWARD. THE STRONGEST AREA OF SHOWERS AND
STORMS MAY REMAIN JUST SOUTH OF THE MAJORITY OF THE FORECAST AREA
BASED OFF THE LATEST HRRR. EVEN SO...STILL CAN NOT RULE OUT SEEING
SOMETHING ACROSS THE CENTRAL MIDLANDS AS THE EVENING PROGRESSES.
INSTABILITY SHOULD INCREASE WITH SOME BREAKS IN THE CLOUDS. SHEAR
VALUES REMAIN HIGH THROUGH THE AFTERNOON AND EVENING...WHICH WOULD
HELP SUPPORT ROTATING STORMS IF ANY CAN PUSH INTO THE AREA. SPC
CONTINUES TO SHOW OUR ENTIRE AREA IN A SLIGHT RISK...WITH AN AREA
OF ENHANCED RISK ACROSS TN/KY.

FOR TONIGHT...MAY STILL SEE ISOLATED TO SCATTERED SHOWERS AS THE
GULF SYSTEM MOVES SOUTH OF THE AREA. BEHIND THE GULF SYSTEM...A WARM
FRONT WILL CONTINUE TO PUSH NORTHWARD THROUGH THE AREA. THE AREA
SHOULD SEE SOME ISENTROPIC LIFT NORTH OF THE FRONT...WHICH WOULD
BRING SOME SHOWERS ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS NOTED ON SUNDAY
BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO WILL
CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
MEDIUM RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. HOWEVER...THERE ARE SOME DIFFERENCES BETWEEN THE LATEST
GFS RUN AND THE PREVIOUS ECMWF FOR THE LATTER PART OF THE PERIOD.
THE PREVIOUS ECMWF SHOWS SOME LINGERING PRECIPITATION OVER THE
AREA FRIDAY WITH HIGH PRESSURE OVER THE AREA SATURDAY. THE LATEST
GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE WEST FRIDAY INTO
SATURDAY...BUT ALSO SHOWS ANOTHER CUT-OFF UPPER LOW FORMING OVER
THE EASTERN GULF COAST. THIS FEATURE COULD SPREAD PRECIPITATION
BACK INTO SC BY LATE SATURDAY. DUE TO UNCERTAINTY...WILL KEEP
FRIDAY AND SATURDAY DRY AT THIS TIME. TEMPERATURES GENERALLY AT
OR JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...

RAIN HAS CONTINUED TO MOVE EAST AND IS NOW OFF OF THE COAST. SHOWERS
ARE NOT EXPECTED TO MOVE BACK INTO THE AREA UNTIL LATE THIS
AFTERNOON INTO THE EVENING. IFR CONDITIONS EXIST UPSTREAM AND WILL
CONTINUE TO FEED WESTWARD. THESE IFR/MVFR CEILINGS SHOULD REMAIN
THROUGH THE AFTERNOON AND OVERNIGHT.

MODELS TEND TO KEEP SHOWER ACTIVITY THIS EVENING TO THE
SOUTH...POSSIBLY SKIRTING ALONG THE CSRA. HOWEVER CONFIDENCE IS LOW
THAT ADDITIONAL RAINFALL WILL OCCUR. IF CONVECTION FORMS IN CENTRAL
GA IT MAY ROB THE MOISTURE NECESSARY FOR SHOWERS IN OUR AREA.

SOUTHEAST TO SOUTHERLY WINDS ARE EXPECTED TODAY UNTIL THE WARM FRONT
LIFTS THROUGH AND THEN WINDS BECOME MORE SOUTHWESTERLY THIS
EVENING. LOW-LEVEL WIND SHEAR MAY CONTINUE TO BE AN ISSUE AS A
STRONG MID-LEVEL JET STRENGTHENS OVERNIGHT. WESTERLY WINDS AND
DOWNSLOPE FLOW ON SUNDAY WILL BEGIN TO SCOUR OUT OVERCAST SKIES.

EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SUNDAY. NO
SIGNIFICANT IMPACTS EXPECTED MONDAY AND TUESDAY. AN APPROACHING
WARM FRONT MAY RESULT IN WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$
















000
FXUS62 KGSP 251727
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
127 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
1715 UTC UPDATE...WINDS WERE UPDATED TO INCORPORATE THE LATEST
NAM GUIDANCE. POPS AND QPF WERE REDUCED FURTHER BASED ON RADAR
TRENDS.

1400 UTC UPDATE...POPS WERE ADJUSTED BASED ON RADAR
TRENDS...FAVORING THE EAST OVER THE WEST. WINDS WERE UPDATED FROM AN
EQUALLY WEIGHTED BLEND OF THE LATEST ADJMAV AND NAM. AREAS OF RAIN
INDUCED FOG WERE UPDATED BASED ON OBSERVATIONS. TEMPERATURE EAST OF
KCLT WERE ADJUSTED SLIGHTLY FOR A BETTER FIT WITH NEIGHBORING
OFFICES.

AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AT KCLT...LOW CONFIDENCE FORECAST...WITH MODEL GUIDANCE QUITE
DIVERGENT. OBSERVATIONS SHOW IFR CIG RESTRICTION...BUT VSBY HAS
IMPROVED BEHIND DEPARTING RAINFALL. MODEL TIME HEIGHTS SUPPORT BRIEF
CIG IMPROVEMENT TO LOW VFR THIS EVENING BEFORE LOWERING TO AT LEAST
MVFR LATE TONIGHT INTO SUNDAY MORNING. GUIDANCE SUPPORTS AN MVFR
VSBY LATE THIS EVENING...BUT SUGGEST A RETURN TO VFR TOWARD DAWN...
OSTENSIBLY DUE TO NE WINDS THAT SET UP OVERNIGHT AS A COLD FRONT
ARRIVES FROM THE N. CONVECTIVE CHANCES APPEAR BEST OVERNIGHT AS THE
FRONT APPROACHES.

ELSEWHERE...CONFIDENCE IS LIMITED AS TRENDS DEPART FORM PREVIOUS
FORECAST...AND MODEL SOLUTIONS DIVERGE. OBSERVED CIG RESTRICTIONS
MAY IMPROVE THIS EVENING BASED ON MODEL TIME HEIGHTS...BUT PROBABLY
NOT AS MUCH AS A MODEL BLEND WOULD SUGGEST. VSBY IMPROVEMENT HAS
BEEN NOTED AS RAINFALL MOVES OFF TO THE EAST...AND THIS TREND IS
EXPECTED OT CONTINUE. TIME HEIGHTS SHOW CIGS LOWERING AGAIN TOWARD
DAWN...AND REMAINING LOW INTO SUNDAY MORNING. VSBY RESTRICTIONS
APPEAR TO RETURN AT KHKY LATE THIS EVENING...THEN END AS A BACK DOOR
COLD FRONT ARRIVES BEFORE DAWN VEERING THE WIND TO THE NE. MODEL
DATA SUPPORTS KAND HAVING A DAYBREAK VSBY RESTRICTION...BUT MODEL
WINDS REMAIN UP...FAVORING VFR. CONVECTIVE CHANCES NOW APPEAR TO BE
BEST OVERNIGHT AHEAD OF THE COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            17-23Z        23-05Z        05-11Z        11-12Z
KCLT       MED   75%     HIGH  83%     LOW   31%     MED   66%
KGSP       HIGH 100%     HIGH  87%     HIGH 100%     HIGH  80%
KAVL       HIGH  83%     LOW   56%     MED   64%     MED   60%
KHKY       MED   75%     HIGH 100%     MED   64%     MED   73%
KGMU       HIGH 100%     HIGH  87%     HIGH  93%     MED   70%
KAND       HIGH 100%     HIGH  81%     HIGH  93%     LOW   53%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...JAT/NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...JAT




000
FXUS62 KCHS 251727
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
127 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
INITIAL CONVECTION HAS PUSHED OFFSHORE AND SATELLITE SHOWS
SIGNIFICANT BREAKS POISED TO AFFECT MUCH OF THE AREA OVER THE NEXT
FEW HOURS. TEMPERATURES SHOULD RISE QUICKLY AS POCKETS OF MORE
DIRECT INSOLATION INCREASE...AS SHOULD SURFACE BASED INSTABILITY.
STILL EXPECT ADDITIONAL REDEVELOPMENT OF TSTMS BY MID-AFTERNOON AS
UPPER FORCING ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE
UPPER JET APPROACHES AND INTERACTS WITH AN INCREASINGLY UNSTABLE
ENVIRONMENT. RAP/NAM INSTABILITY PARAMETERS STILL SUPPORT A
CONDITIONAL RISK FOR DAMAGING WINDS AND TORNADOES LATER THIS
AFTERNOON AS A POSSIBLE QLCS MOVES THROUGH. HIGH RESOLUTION
GUIDANCE STILL SUGGESTS AREAS ALONG/SOUTH OF A METTER-BEAUFORT
LINE HAVE THE HIGHER PROBABILITIES FOR SEVERE WEATHER WITH THE
BULK OF ANY QLCS LIKELY AFFECTING AREAS SOUTH OF I-16.

HAVE ADJUSTED POPS/SKY COVER TO ACCOUNT FOR SHORT TERM TRENDS. A
TORNADO WATCH MAY BE NEEDED LATER THIS AFTERNOON FOR PARTS OF
SOUTHEAST GEORGIA AND POSSIBLY FAR SOUTHERN SOUTH CAROLINA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND
SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE
DISTURBANCE. LOWS SHOULD BE IN THE MID TO UPPER 6S ACROSS THE
AREA.

SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS TO
25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUE
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KGSP 251727
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
127 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
1715 UTC UPDATE...WINDS WERE UPDATED TO INCORPORATE THE LATEST
NAM GUIDANCE. POPS AND QPF WERE REDUCED FURTHER BASED ON RADAR
TRENDS.

1400 UTC UPDATE...POPS WERE ADJUSTED BASED ON RADAR
TRENDS...FAVORING THE EAST OVER THE WEST. WINDS WERE UPDATED FROM AN
EQUALLY WEIGHTED BLEND OF THE LATEST ADJMAV AND NAM. AREAS OF RAIN
INDUCED FOG WERE UPDATED BASED ON OBSERVATIONS. TEMPERATURE EAST OF
KCLT WERE ADJUSTED SLIGHTLY FOR A BETTER FIT WITH NEIGHBORING
OFFICES.

AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AT KCLT...LOW CONFIDENCE FORECAST...WITH MODEL GUIDANCE QUITE
DIVERGENT. OBSERVATIONS SHOW IFR CIG RESTRICTION...BUT VSBY HAS
IMPROVED BEHIND DEPARTING RAINFALL. MODEL TIME HEIGHTS SUPPORT BRIEF
CIG IMPROVEMENT TO LOW VFR THIS EVENING BEFORE LOWERING TO AT LEAST
MVFR LATE TONIGHT INTO SUNDAY MORNING. GUIDANCE SUPPORTS AN MVFR
VSBY LATE THIS EVENING...BUT SUGGEST A RETURN TO VFR TOWARD DAWN...
OSTENSIBLY DUE TO NE WINDS THAT SET UP OVERNIGHT AS A COLD FRONT
ARRIVES FROM THE N. CONVECTIVE CHANCES APPEAR BEST OVERNIGHT AS THE
FRONT APPROACHES.

ELSEWHERE...CONFIDENCE IS LIMITED AS TRENDS DEPART FORM PREVIOUS
FORECAST...AND MODEL SOLUTIONS DIVERGE. OBSERVED CIG RESTRICTIONS
MAY IMPROVE THIS EVENING BASED ON MODEL TIME HEIGHTS...BUT PROBABLY
NOT AS MUCH AS A MODEL BLEND WOULD SUGGEST. VSBY IMPROVEMENT HAS
BEEN NOTED AS RAINFALL MOVES OFF TO THE EAST...AND THIS TREND IS
EXPECTED OT CONTINUE. TIME HEIGHTS SHOW CIGS LOWERING AGAIN TOWARD
DAWN...AND REMAINING LOW INTO SUNDAY MORNING. VSBY RESTRICTIONS
APPEAR TO RETURN AT KHKY LATE THIS EVENING...THEN END AS A BACK DOOR
COLD FRONT ARRIVES BEFORE DAWN VEERING THE WIND TO THE NE. MODEL
DATA SUPPORTS KAND HAVING A DAYBREAK VSBY RESTRICTION...BUT MODEL
WINDS REMAIN UP...FAVORING VFR. CONVECTIVE CHANCES NOW APPEAR TO BE
BEST OVERNIGHT AHEAD OF THE COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            17-23Z        23-05Z        05-11Z        11-12Z
KCLT       MED   75%     HIGH  83%     LOW   31%     MED   66%
KGSP       HIGH 100%     HIGH  87%     HIGH 100%     HIGH  80%
KAVL       HIGH  83%     LOW   56%     MED   64%     MED   60%
KHKY       MED   75%     HIGH 100%     MED   64%     MED   73%
KGMU       HIGH 100%     HIGH  87%     HIGH  93%     MED   70%
KAND       HIGH 100%     HIGH  81%     HIGH  93%     LOW   53%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...JAT/NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...JAT



000
FXUS62 KCHS 251727
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
127 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
INITIAL CONVECTION HAS PUSHED OFFSHORE AND SATELLITE SHOWS
SIGNIFICANT BREAKS POISED TO AFFECT MUCH OF THE AREA OVER THE NEXT
FEW HOURS. TEMPERATURES SHOULD RISE QUICKLY AS POCKETS OF MORE
DIRECT INSOLATION INCREASE...AS SHOULD SURFACE BASED INSTABILITY.
STILL EXPECT ADDITIONAL REDEVELOPMENT OF TSTMS BY MID-AFTERNOON AS
UPPER FORCING ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE
UPPER JET APPROACHES AND INTERACTS WITH AN INCREASINGLY UNSTABLE
ENVIRONMENT. RAP/NAM INSTABILITY PARAMETERS STILL SUPPORT A
CONDITIONAL RISK FOR DAMAGING WINDS AND TORNADOES LATER THIS
AFTERNOON AS A POSSIBLE QLCS MOVES THROUGH. HIGH RESOLUTION
GUIDANCE STILL SUGGESTS AREAS ALONG/SOUTH OF A METTER-BEAUFORT
LINE HAVE THE HIGHER PROBABILITIES FOR SEVERE WEATHER WITH THE
BULK OF ANY QLCS LIKELY AFFECTING AREAS SOUTH OF I-16.

HAVE ADJUSTED POPS/SKY COVER TO ACCOUNT FOR SHORT TERM TRENDS. A
TORNADO WATCH MAY BE NEEDED LATER THIS AFTERNOON FOR PARTS OF
SOUTHEAST GEORGIA AND POSSIBLY FAR SOUTHERN SOUTH CAROLINA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND
SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE
DISTURBANCE. LOWS SHOULD BE IN THE MID TO UPPER 6S ACROSS THE
AREA.

SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS TO
25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUE
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KGSP 251727
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
127 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
1715 UTC UPDATE...WINDS WERE UPDATED TO INCORPORATE THE LATEST
NAM GUIDANCE. POPS AND QPF WERE REDUCED FURTHER BASED ON RADAR
TRENDS.

1400 UTC UPDATE...POPS WERE ADJUSTED BASED ON RADAR
TRENDS...FAVORING THE EAST OVER THE WEST. WINDS WERE UPDATED FROM AN
EQUALLY WEIGHTED BLEND OF THE LATEST ADJMAV AND NAM. AREAS OF RAIN
INDUCED FOG WERE UPDATED BASED ON OBSERVATIONS. TEMPERATURE EAST OF
KCLT WERE ADJUSTED SLIGHTLY FOR A BETTER FIT WITH NEIGHBORING
OFFICES.

AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AT KCLT...LOW CONFIDENCE FORECAST...WITH MODEL GUIDANCE QUITE
DIVERGENT. OBSERVATIONS SHOW IFR CIG RESTRICTION...BUT VSBY HAS
IMPROVED BEHIND DEPARTING RAINFALL. MODEL TIME HEIGHTS SUPPORT BRIEF
CIG IMPROVEMENT TO LOW VFR THIS EVENING BEFORE LOWERING TO AT LEAST
MVFR LATE TONIGHT INTO SUNDAY MORNING. GUIDANCE SUPPORTS AN MVFR
VSBY LATE THIS EVENING...BUT SUGGEST A RETURN TO VFR TOWARD DAWN...
OSTENSIBLY DUE TO NE WINDS THAT SET UP OVERNIGHT AS A COLD FRONT
ARRIVES FROM THE N. CONVECTIVE CHANCES APPEAR BEST OVERNIGHT AS THE
FRONT APPROACHES.

ELSEWHERE...CONFIDENCE IS LIMITED AS TRENDS DEPART FORM PREVIOUS
FORECAST...AND MODEL SOLUTIONS DIVERGE. OBSERVED CIG RESTRICTIONS
MAY IMPROVE THIS EVENING BASED ON MODEL TIME HEIGHTS...BUT PROBABLY
NOT AS MUCH AS A MODEL BLEND WOULD SUGGEST. VSBY IMPROVEMENT HAS
BEEN NOTED AS RAINFALL MOVES OFF TO THE EAST...AND THIS TREND IS
EXPECTED OT CONTINUE. TIME HEIGHTS SHOW CIGS LOWERING AGAIN TOWARD
DAWN...AND REMAINING LOW INTO SUNDAY MORNING. VSBY RESTRICTIONS
APPEAR TO RETURN AT KHKY LATE THIS EVENING...THEN END AS A BACK DOOR
COLD FRONT ARRIVES BEFORE DAWN VEERING THE WIND TO THE NE. MODEL
DATA SUPPORTS KAND HAVING A DAYBREAK VSBY RESTRICTION...BUT MODEL
WINDS REMAIN UP...FAVORING VFR. CONVECTIVE CHANCES NOW APPEAR TO BE
BEST OVERNIGHT AHEAD OF THE COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            17-23Z        23-05Z        05-11Z        11-12Z
KCLT       MED   75%     HIGH  83%     LOW   31%     MED   66%
KGSP       HIGH 100%     HIGH  87%     HIGH 100%     HIGH  80%
KAVL       HIGH  83%     LOW   56%     MED   64%     MED   60%
KHKY       MED   75%     HIGH 100%     MED   64%     MED   73%
KGMU       HIGH 100%     HIGH  87%     HIGH  93%     MED   70%
KAND       HIGH 100%     HIGH  81%     HIGH  93%     LOW   53%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...JAT/NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...JAT



000
FXUS62 KCHS 251727
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
127 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
INITIAL CONVECTION HAS PUSHED OFFSHORE AND SATELLITE SHOWS
SIGNIFICANT BREAKS POISED TO AFFECT MUCH OF THE AREA OVER THE NEXT
FEW HOURS. TEMPERATURES SHOULD RISE QUICKLY AS POCKETS OF MORE
DIRECT INSOLATION INCREASE...AS SHOULD SURFACE BASED INSTABILITY.
STILL EXPECT ADDITIONAL REDEVELOPMENT OF TSTMS BY MID-AFTERNOON AS
UPPER FORCING ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE
UPPER JET APPROACHES AND INTERACTS WITH AN INCREASINGLY UNSTABLE
ENVIRONMENT. RAP/NAM INSTABILITY PARAMETERS STILL SUPPORT A
CONDITIONAL RISK FOR DAMAGING WINDS AND TORNADOES LATER THIS
AFTERNOON AS A POSSIBLE QLCS MOVES THROUGH. HIGH RESOLUTION
GUIDANCE STILL SUGGESTS AREAS ALONG/SOUTH OF A METTER-BEAUFORT
LINE HAVE THE HIGHER PROBABILITIES FOR SEVERE WEATHER WITH THE
BULK OF ANY QLCS LIKELY AFFECTING AREAS SOUTH OF I-16.

HAVE ADJUSTED POPS/SKY COVER TO ACCOUNT FOR SHORT TERM TRENDS. A
TORNADO WATCH MAY BE NEEDED LATER THIS AFTERNOON FOR PARTS OF
SOUTHEAST GEORGIA AND POSSIBLY FAR SOUTHERN SOUTH CAROLINA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND
SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE
DISTURBANCE. LOWS SHOULD BE IN THE MID TO UPPER 6S ACROSS THE
AREA.

SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS TO
25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUE
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KGSP 251727
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
127 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
1715 UTC UPDATE...WINDS WERE UPDATED TO INCORPORATE THE LATEST
NAM GUIDANCE. POPS AND QPF WERE REDUCED FURTHER BASED ON RADAR
TRENDS.

1400 UTC UPDATE...POPS WERE ADJUSTED BASED ON RADAR
TRENDS...FAVORING THE EAST OVER THE WEST. WINDS WERE UPDATED FROM AN
EQUALLY WEIGHTED BLEND OF THE LATEST ADJMAV AND NAM. AREAS OF RAIN
INDUCED FOG WERE UPDATED BASED ON OBSERVATIONS. TEMPERATURE EAST OF
KCLT WERE ADJUSTED SLIGHTLY FOR A BETTER FIT WITH NEIGHBORING
OFFICES.

AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AT KCLT...LOW CONFIDENCE FORECAST...WITH MODEL GUIDANCE QUITE
DIVERGENT. OBSERVATIONS SHOW IFR CIG RESTRICTION...BUT VSBY HAS
IMPROVED BEHIND DEPARTING RAINFALL. MODEL TIME HEIGHTS SUPPORT BRIEF
CIG IMPROVEMENT TO LOW VFR THIS EVENING BEFORE LOWERING TO AT LEAST
MVFR LATE TONIGHT INTO SUNDAY MORNING. GUIDANCE SUPPORTS AN MVFR
VSBY LATE THIS EVENING...BUT SUGGEST A RETURN TO VFR TOWARD DAWN...
OSTENSIBLY DUE TO NE WINDS THAT SET UP OVERNIGHT AS A COLD FRONT
ARRIVES FROM THE N. CONVECTIVE CHANCES APPEAR BEST OVERNIGHT AS THE
FRONT APPROACHES.

ELSEWHERE...CONFIDENCE IS LIMITED AS TRENDS DEPART FORM PREVIOUS
FORECAST...AND MODEL SOLUTIONS DIVERGE. OBSERVED CIG RESTRICTIONS
MAY IMPROVE THIS EVENING BASED ON MODEL TIME HEIGHTS...BUT PROBABLY
NOT AS MUCH AS A MODEL BLEND WOULD SUGGEST. VSBY IMPROVEMENT HAS
BEEN NOTED AS RAINFALL MOVES OFF TO THE EAST...AND THIS TREND IS
EXPECTED OT CONTINUE. TIME HEIGHTS SHOW CIGS LOWERING AGAIN TOWARD
DAWN...AND REMAINING LOW INTO SUNDAY MORNING. VSBY RESTRICTIONS
APPEAR TO RETURN AT KHKY LATE THIS EVENING...THEN END AS A BACK DOOR
COLD FRONT ARRIVES BEFORE DAWN VEERING THE WIND TO THE NE. MODEL
DATA SUPPORTS KAND HAVING A DAYBREAK VSBY RESTRICTION...BUT MODEL
WINDS REMAIN UP...FAVORING VFR. CONVECTIVE CHANCES NOW APPEAR TO BE
BEST OVERNIGHT AHEAD OF THE COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            17-23Z        23-05Z        05-11Z        11-12Z
KCLT       MED   75%     HIGH  83%     LOW   31%     MED   66%
KGSP       HIGH 100%     HIGH  87%     HIGH 100%     HIGH  80%
KAVL       HIGH  83%     LOW   56%     MED   64%     MED   60%
KHKY       MED   75%     HIGH 100%     MED   64%     MED   73%
KGMU       HIGH 100%     HIGH  87%     HIGH  93%     MED   70%
KAND       HIGH 100%     HIGH  81%     HIGH  93%     LOW   53%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...JAT/NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...JAT




000
FXUS62 KCHS 251727
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
127 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
INITIAL CONVECTION HAS PUSHED OFFSHORE AND SATELLITE SHOWS
SIGNIFICANT BREAKS POISED TO AFFECT MUCH OF THE AREA OVER THE NEXT
FEW HOURS. TEMPERATURES SHOULD RISE QUICKLY AS POCKETS OF MORE
DIRECT INSOLATION INCREASE...AS SHOULD SURFACE BASED INSTABILITY.
STILL EXPECT ADDITIONAL REDEVELOPMENT OF TSTMS BY MID-AFTERNOON AS
UPPER FORCING ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE
UPPER JET APPROACHES AND INTERACTS WITH AN INCREASINGLY UNSTABLE
ENVIRONMENT. RAP/NAM INSTABILITY PARAMETERS STILL SUPPORT A
CONDITIONAL RISK FOR DAMAGING WINDS AND TORNADOES LATER THIS
AFTERNOON AS A POSSIBLE QLCS MOVES THROUGH. HIGH RESOLUTION
GUIDANCE STILL SUGGESTS AREAS ALONG/SOUTH OF A METTER-BEAUFORT
LINE HAVE THE HIGHER PROBABILITIES FOR SEVERE WEATHER WITH THE
BULK OF ANY QLCS LIKELY AFFECTING AREAS SOUTH OF I-16.

HAVE ADJUSTED POPS/SKY COVER TO ACCOUNT FOR SHORT TERM TRENDS. A
TORNADO WATCH MAY BE NEEDED LATER THIS AFTERNOON FOR PARTS OF
SOUTHEAST GEORGIA AND POSSIBLY FAR SOUTHERN SOUTH CAROLINA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND
SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE
DISTURBANCE. LOWS SHOULD BE IN THE MID TO UPPER 6S ACROSS THE
AREA.

SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS TO
25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUE
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KGSP 251727
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
127 PM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM KENTUCKY AND
TENNESSEE TO NORTH CAROLINA TONIGHT...THEN OFF THE COAST ON
SUNDAY.  COOL AND DRY HIGH PRESSURE DROPS DOWN FROM CENTRAL
CANADA SUNDAY AND WILL BE OUR WEATHER MAKER FOR THE FIRST HALF OF
THE WEEK.  EXPECT LOW PRESSURE TO MOVE EAST FROM TEXAS IN MID WEEK
AND BRING MORE RAIN WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
1715 UTC UPDATE...WINDS WERE UPDATED TO INCORPORATE THE LATEST
NAM GUIDANCE. POPS AND QPF WERE REDUCED FURTHER BASED ON RADAR
TRENDS.

1400 UTC UPDATE...POPS WERE ADJUSTED BASED ON RADAR
TRENDS...FAVORING THE EAST OVER THE WEST. WINDS WERE UPDATED FROM AN
EQUALLY WEIGHTED BLEND OF THE LATEST ADJMAV AND NAM. AREAS OF RAIN
INDUCED FOG WERE UPDATED BASED ON OBSERVATIONS. TEMPERATURE EAST OF
KCLT WERE ADJUSTED SLIGHTLY FOR A BETTER FIT WITH NEIGHBORING
OFFICES.

AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AT KCLT...LOW CONFIDENCE FORECAST...WITH MODEL GUIDANCE QUITE
DIVERGENT. OBSERVATIONS SHOW IFR CIG RESTRICTION...BUT VSBY HAS
IMPROVED BEHIND DEPARTING RAINFALL. MODEL TIME HEIGHTS SUPPORT BRIEF
CIG IMPROVEMENT TO LOW VFR THIS EVENING BEFORE LOWERING TO AT LEAST
MVFR LATE TONIGHT INTO SUNDAY MORNING. GUIDANCE SUPPORTS AN MVFR
VSBY LATE THIS EVENING...BUT SUGGEST A RETURN TO VFR TOWARD DAWN...
OSTENSIBLY DUE TO NE WINDS THAT SET UP OVERNIGHT AS A COLD FRONT
ARRIVES FROM THE N. CONVECTIVE CHANCES APPEAR BEST OVERNIGHT AS THE
FRONT APPROACHES.

ELSEWHERE...CONFIDENCE IS LIMITED AS TRENDS DEPART FORM PREVIOUS
FORECAST...AND MODEL SOLUTIONS DIVERGE. OBSERVED CIG RESTRICTIONS
MAY IMPROVE THIS EVENING BASED ON MODEL TIME HEIGHTS...BUT PROBABLY
NOT AS MUCH AS A MODEL BLEND WOULD SUGGEST. VSBY IMPROVEMENT HAS
BEEN NOTED AS RAINFALL MOVES OFF TO THE EAST...AND THIS TREND IS
EXPECTED OT CONTINUE. TIME HEIGHTS SHOW CIGS LOWERING AGAIN TOWARD
DAWN...AND REMAINING LOW INTO SUNDAY MORNING. VSBY RESTRICTIONS
APPEAR TO RETURN AT KHKY LATE THIS EVENING...THEN END AS A BACK DOOR
COLD FRONT ARRIVES BEFORE DAWN VEERING THE WIND TO THE NE. MODEL
DATA SUPPORTS KAND HAVING A DAYBREAK VSBY RESTRICTION...BUT MODEL
WINDS REMAIN UP...FAVORING VFR. CONVECTIVE CHANCES NOW APPEAR TO BE
BEST OVERNIGHT AHEAD OF THE COLD FRONT.

OUTLOOK...A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            17-23Z        23-05Z        05-11Z        11-12Z
KCLT       MED   75%     HIGH  83%     LOW   31%     MED   66%
KGSP       HIGH 100%     HIGH  87%     HIGH 100%     HIGH  80%
KAVL       HIGH  83%     LOW   56%     MED   64%     MED   60%
KHKY       MED   75%     HIGH 100%     MED   64%     MED   73%
KGMU       HIGH 100%     HIGH  87%     HIGH  93%     MED   70%
KAND       HIGH 100%     HIGH  81%     HIGH  93%     LOW   53%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...JAT/NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...JAT



000
FXUS62 KCHS 251727
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
127 PM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
INITIAL CONVECTION HAS PUSHED OFFSHORE AND SATELLITE SHOWS
SIGNIFICANT BREAKS POISED TO AFFECT MUCH OF THE AREA OVER THE NEXT
FEW HOURS. TEMPERATURES SHOULD RISE QUICKLY AS POCKETS OF MORE
DIRECT INSOLATION INCREASE...AS SHOULD SURFACE BASED INSTABILITY.
STILL EXPECT ADDITIONAL REDEVELOPMENT OF TSTMS BY MID-AFTERNOON AS
UPPER FORCING ASSOCIATED WITH THE RIGHT ENTRANCE REGION OF THE
UPPER JET APPROACHES AND INTERACTS WITH AN INCREASINGLY UNSTABLE
ENVIRONMENT. RAP/NAM INSTABILITY PARAMETERS STILL SUPPORT A
CONDITIONAL RISK FOR DAMAGING WINDS AND TORNADOES LATER THIS
AFTERNOON AS A POSSIBLE QLCS MOVES THROUGH. HIGH RESOLUTION
GUIDANCE STILL SUGGESTS AREAS ALONG/SOUTH OF A METTER-BEAUFORT
LINE HAVE THE HIGHER PROBABILITIES FOR SEVERE WEATHER WITH THE
BULK OF ANY QLCS LIKELY AFFECTING AREAS SOUTH OF I-16.

HAVE ADJUSTED POPS/SKY COVER TO ACCOUNT FOR SHORT TERM TRENDS. A
TORNADO WATCH MAY BE NEEDED LATER THIS AFTERNOON FOR PARTS OF
SOUTHEAST GEORGIA AND POSSIBLY FAR SOUTHERN SOUTH CAROLINA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND
SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE
DISTURBANCE. LOWS SHOULD BE IN THE MID TO UPPER 6S ACROSS THE
AREA.

SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL RETURN TO VFR SHORTLY AT BOTH KCHS/KSAV IN THE
WAKE OF SHOWERS/TSTMS. EXPECT TSTMS TO REDEVELOP ALONG/SOUTH I-16
OVER THE NEXT FEW HOURS WHICH COULD IMPACT KSAV. INTRODUCED A
TEMPO GROUP FROM 22-01Z TO ACCOUNT FOR THIS. NO IMPACTS ARE
EXPECTED ATTM AT KCHS. ACTIVITY WILL DIMINISH BY MID-EVENING WITH
VFR PREVAILING. SOME CONCERN FOR CIGS/PATCHY FOG TO REDEVELOP LATE
AS SKIES CLEAR...BUT ENOUGH WIND SHOULD PREVENT TOO MUCH FOG.
BETTER CHANCES FOR CIGS WILL BE KSAV WHERE MORE RAIN WILL FALL.
WILL SHOW MVFR CIGS THERE FROM 09-12Z...BUT KEEP KCHS VFR FOR NOW.

EXTENDED AVIATION OUTLOOK...BREEZY SUNDAY AFTERNOON WITH GUSTS TO
25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL INTO TUE
BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KCAE 251539
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1139 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT LIFTING NORTHWARD INTO THE AREA TODAY WILL BE THE FOCUS
FOR SHOWERS AND SOME THUNDERSTORMS TODAY. DRIER WEATHER RETURNS FOR
SUNDAY AS A COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...A WARM FRONT WILL LIFT NORTHWARD INTO THE AREA
TODAY. PRECIPITABLE WATER VALUES INCREASE TO NEAR 1.80 INCHES FOR
THIS AFTERNOON. ONE AREA OF SHOWERS HAS NOW PUSHED OFF TO THE EAST
OF MUCH OF THE CWA. MODELS STILL HINTING AT THE POSSIBILITY OF
ADDITIONAL DEVELOPMENT BACK ACROSS CENTRAL GA LATER THIS
AFTERNOON. STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST
SOUTH OF THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST
HRRR. EVEN SO...STILL CAN NOT RULE OUT SEEING SOMETHING ACROSS THE
CENTRAL MIDLANDS AS THE EVENING PROGRESSES. INSTABILITY SHOULD
INCREASE WITH SOME BREAKS IN THE CLOUDS. SHEAR VALUES REMAIN HIGH
THROUGH THE AFTERNOON AND EVENING...WHICH WOULD HELP SUPPORT
ROTATING STORMS IF ANY CAN PUSH INTO THE AREA. SPC CONTINUES TO
SHOW OUR ENTIRE AREA IN A SLIGHT RISK...WITH AN AREA OF ENHANCED
RISK ACROSS TN/KY.

TEMPERATURES TODAY WILL BE LIMITED BY THE CLOUDS AND RAINFALL FOR
MUCH OF THE DAY BUT THERE IS SOME UNCERTAINTY ABOUT SOME POSSIBLE
RECOVERY LATE. WE SHOULD SEE A GRADIENT IN TEMPS FROM THE 60S
NORTH TO 70S SOUTH.

TONIGHT...SHOULD SEE SOME LINGERING SHOWERS AND ISOLATED
THUNDERSTORMS LATE THIS EVENING INTO THE OVERNIGHT HOURS. AS THE
WARM FRONT PUSHES FURTHER NORTHWARD...DO EXPECT SHOWERS TO BECOME
MORE CONCENTRATED ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS NOTED ON SUNDAY
BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO WILL
CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
MEDIUM RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. LATEST GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE
WEST FRIDAY. TEMPERATURES GENERALLY AT OR JUST BELOW NORMAL
THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
AREA OF LIGHT RAIN HAS NOW MOVED OFF TO THE EAST OF ALL TERMINALS.
REGIONAL OBS SHOWING IFR STRATUS DECK MOVING IN BEHIND THIS
RAINFALL...AND HAVE AMENDED ALL TAFS TO ACCOUNT FOR LOWER CEILINGS
MOVING INTO THE REGION. THESE IFR CEILINGS SHOULD REMAIN THROUGH
THE AFTERNOON AND INTO THE EVENING. REGIONAL MODELS INDICATE
ADDITIONAL SHOWER/STORM DEVELOPMENT POSSIBLE ACROSS CENTRAL GA
LATER THIS AFTERNOON...WITH THE BULK OF THE ACTIVITY POSSIBLY
REMAINING JUST SOUTH OF ALL TAF SITES. CONFIDENCE NOT HIGH THAT
ANY ADDITIONAL RAINFALL WILL IMPACT TAFS SITES THIS AFTERNOON...SO
HAVE REMOVED MENTION OF VCSH FOR NOW.

SOUTHEAST TO SOUTHERLY WINDS EXPECTED TODAY UNTIL THE WARM FRONT
LIFTS THROUGH AND THEN WINDS BECOME MORE SOUTHWESTERLY THIS
EVENING. LOW-LEVEL WIND SHEAR WILL CONTINUE TO BE AN ISSUE INTO
THE AFTERNOON.

EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SUNDAY. NO
SIGNIFICANT IMPACTS EXPECTED MONDAY AND TUESDAY. AN APPROACHING
WARM FRONT MAY RESULT IN WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$








000
FXUS62 KCAE 251539
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1139 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT LIFTING NORTHWARD INTO THE AREA TODAY WILL BE THE FOCUS
FOR SHOWERS AND SOME THUNDERSTORMS TODAY. DRIER WEATHER RETURNS FOR
SUNDAY AS A COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...A WARM FRONT WILL LIFT NORTHWARD INTO THE AREA
TODAY. PRECIPITABLE WATER VALUES INCREASE TO NEAR 1.80 INCHES FOR
THIS AFTERNOON. ONE AREA OF SHOWERS HAS NOW PUSHED OFF TO THE EAST
OF MUCH OF THE CWA. MODELS STILL HINTING AT THE POSSIBILITY OF
ADDITIONAL DEVELOPMENT BACK ACROSS CENTRAL GA LATER THIS
AFTERNOON. STRONGEST AREA OF SHOWERS AND STORMS MAY REMAIN JUST
SOUTH OF THE MAJORITY OF THE FORECAST AREA BASED OFF THE LATEST
HRRR. EVEN SO...STILL CAN NOT RULE OUT SEEING SOMETHING ACROSS THE
CENTRAL MIDLANDS AS THE EVENING PROGRESSES. INSTABILITY SHOULD
INCREASE WITH SOME BREAKS IN THE CLOUDS. SHEAR VALUES REMAIN HIGH
THROUGH THE AFTERNOON AND EVENING...WHICH WOULD HELP SUPPORT
ROTATING STORMS IF ANY CAN PUSH INTO THE AREA. SPC CONTINUES TO
SHOW OUR ENTIRE AREA IN A SLIGHT RISK...WITH AN AREA OF ENHANCED
RISK ACROSS TN/KY.

TEMPERATURES TODAY WILL BE LIMITED BY THE CLOUDS AND RAINFALL FOR
MUCH OF THE DAY BUT THERE IS SOME UNCERTAINTY ABOUT SOME POSSIBLE
RECOVERY LATE. WE SHOULD SEE A GRADIENT IN TEMPS FROM THE 60S
NORTH TO 70S SOUTH.

TONIGHT...SHOULD SEE SOME LINGERING SHOWERS AND ISOLATED
THUNDERSTORMS LATE THIS EVENING INTO THE OVERNIGHT HOURS. AS THE
WARM FRONT PUSHES FURTHER NORTHWARD...DO EXPECT SHOWERS TO BECOME
MORE CONCENTRATED ACROSS NORTHERN COUNTIES...WITH MUCH LESS
ACTIVITY CENTRAL AND SOUTH. OVERNIGHT LOWS REMAIN MILD...ONLY
FALLING INTO THE LOWER TO MIDDLE 60S.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS NOTED ON SUNDAY
BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO WILL
CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
MEDIUM RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. LATEST GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE
WEST FRIDAY. TEMPERATURES GENERALLY AT OR JUST BELOW NORMAL
THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
AREA OF LIGHT RAIN HAS NOW MOVED OFF TO THE EAST OF ALL TERMINALS.
REGIONAL OBS SHOWING IFR STRATUS DECK MOVING IN BEHIND THIS
RAINFALL...AND HAVE AMENDED ALL TAFS TO ACCOUNT FOR LOWER CEILINGS
MOVING INTO THE REGION. THESE IFR CEILINGS SHOULD REMAIN THROUGH
THE AFTERNOON AND INTO THE EVENING. REGIONAL MODELS INDICATE
ADDITIONAL SHOWER/STORM DEVELOPMENT POSSIBLE ACROSS CENTRAL GA
LATER THIS AFTERNOON...WITH THE BULK OF THE ACTIVITY POSSIBLY
REMAINING JUST SOUTH OF ALL TAF SITES. CONFIDENCE NOT HIGH THAT
ANY ADDITIONAL RAINFALL WILL IMPACT TAFS SITES THIS AFTERNOON...SO
HAVE REMOVED MENTION OF VCSH FOR NOW.

SOUTHEAST TO SOUTHERLY WINDS EXPECTED TODAY UNTIL THE WARM FRONT
LIFTS THROUGH AND THEN WINDS BECOME MORE SOUTHWESTERLY THIS
EVENING. LOW-LEVEL WIND SHEAR WILL CONTINUE TO BE AN ISSUE INTO
THE AFTERNOON.

EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SUNDAY. NO
SIGNIFICANT IMPACTS EXPECTED MONDAY AND TUESDAY. AN APPROACHING
WARM FRONT MAY RESULT IN WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KCHS 251527
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1127 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MESOSCALE UPDATE...LINE OF TSTMS EXTENDING FROM DENMARK SOUTH
THROUGH CLAXTON AND HUGHLAND IS MOVING QUICKLY EAST AND IS ON
TRACK TO MOVE OVER LIBERTY...BRYAN...LONG AND POSSIBLY SOUTHERN
CHATHAM COUNTY WITHIN THE HOUR. INSTABILITY AHEAD OF THE LINE IS
MARGINAL AT BEST.

ACTIVITY IS PROGGED TO CLEAR THE COAST 18-19Z WITH HIGH RES
GUIDANCE SHOWING SIGNIFICANT POST CONVECTION RECOVERY /TEMPS
SOARING INTO THE 80S/ OCCURRING THROUGH 21Z BEFORE ANOTHER LINE OF
TSTMS POTENTIALLY MOVES IN AND AFFECTS AREAS SOUTH OF I-16 LATER
THIS AFTERNOON. THIS IS THE LINE OF TSTMS THAT COULD POSE A MORE
SUBSTANTIAL RISK FOR SEVERE WEATHER SHOULD THE RECOVERY OCCUR. IT
IS UNCLEAR HOW FAR NORTH THIS LINE COULD REACH...BUT STILL THINK
AREAS ALONG/SOUTH OF A METTER-BEAUFORT LINE OF THE BEST
CONDITIONAL PROBABILITIES FOR SEVERE TSTMS LATER TODAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND
SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE
DISTURBANCE. LOWS SHOULD BE IN THE MID TO UPPER 6S ACROSS THE
AREA.

SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL AT KCHS AND KSAV UNTIL CONDITIONS
BEGIN TO DETERIORATE AROUND MIDDAY AS SHOWERS AND THUNDERSTORMS
SPREAD ACROSS THE AREA AS A WARM FRONT LIFTS NORTH. EXPECT MVFR OR
LOWER CONDITIONS TO DEVELOP WITHIN THE SHOWERS AND
THUNDERSTORMS...ROUGHLY IN THE 16-23Z TIME FRAME. THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING STRONG/ERRATIC WINDS...HEAVY RAIN AND
FREQUENT LIGHTNING. EVEN OUTSIDE OF CONVECTION...WINDS WILL BE
BREEZY THIS AFTERNOON WITH GUSTS UPWARDS OF AROUND 20 KT. SOME
SHOWERS COULD LINGER INTO LATE THIS EVENING...BUT VFR CONDITIONS
ARE GENERALLY EXPECTED ONCE THE BULK OF THE CONVECTION MOVES
THROUGH. LINGERING LOW LEVEL MOISTURE COULD PRODUCE SOME MVFR OR
LOWER CEILINGS TOWARD DAYBREAK SUNDAY. LOW LEVEL WIND SHEAR COULD
BE A FACTOR AT BOTH TERMINALS AFTER 03Z AS WINDS INCREASE TO
35-40 KT WITHIN 2K FT OF THE SURFACE.

EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN MVFR CIGS SUNDAY
NIGHT WITH A COLD FRONTAL PASSAGE. BREEZY SUNDAY AFTERNOON WITH
GUSTS TO 25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL
INTO TUE BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KCHS 251527
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1127 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MESOSCALE UPDATE...LINE OF TSTMS EXTENDING FROM DENMARK SOUTH
THROUGH CLAXTON AND HUGHLAND IS MOVING QUICKLY EAST AND IS ON
TRACK TO MOVE OVER LIBERTY...BRYAN...LONG AND POSSIBLY SOUTHERN
CHATHAM COUNTY WITHIN THE HOUR. INSTABILITY AHEAD OF THE LINE IS
MARGINAL AT BEST.

ACTIVITY IS PROGGED TO CLEAR THE COAST 18-19Z WITH HIGH RES
GUIDANCE SHOWING SIGNIFICANT POST CONVECTION RECOVERY /TEMPS
SOARING INTO THE 80S/ OCCURRING THROUGH 21Z BEFORE ANOTHER LINE OF
TSTMS POTENTIALLY MOVES IN AND AFFECTS AREAS SOUTH OF I-16 LATER
THIS AFTERNOON. THIS IS THE LINE OF TSTMS THAT COULD POSE A MORE
SUBSTANTIAL RISK FOR SEVERE WEATHER SHOULD THE RECOVERY OCCUR. IT
IS UNCLEAR HOW FAR NORTH THIS LINE COULD REACH...BUT STILL THINK
AREAS ALONG/SOUTH OF A METTER-BEAUFORT LINE OF THE BEST
CONDITIONAL PROBABILITIES FOR SEVERE TSTMS LATER TODAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND
SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE
DISTURBANCE. LOWS SHOULD BE IN THE MID TO UPPER 6S ACROSS THE
AREA.

SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL AT KCHS AND KSAV UNTIL CONDITIONS
BEGIN TO DETERIORATE AROUND MIDDAY AS SHOWERS AND THUNDERSTORMS
SPREAD ACROSS THE AREA AS A WARM FRONT LIFTS NORTH. EXPECT MVFR OR
LOWER CONDITIONS TO DEVELOP WITHIN THE SHOWERS AND
THUNDERSTORMS...ROUGHLY IN THE 16-23Z TIME FRAME. THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING STRONG/ERRATIC WINDS...HEAVY RAIN AND
FREQUENT LIGHTNING. EVEN OUTSIDE OF CONVECTION...WINDS WILL BE
BREEZY THIS AFTERNOON WITH GUSTS UPWARDS OF AROUND 20 KT. SOME
SHOWERS COULD LINGER INTO LATE THIS EVENING...BUT VFR CONDITIONS
ARE GENERALLY EXPECTED ONCE THE BULK OF THE CONVECTION MOVES
THROUGH. LINGERING LOW LEVEL MOISTURE COULD PRODUCE SOME MVFR OR
LOWER CEILINGS TOWARD DAYBREAK SUNDAY. LOW LEVEL WIND SHEAR COULD
BE A FACTOR AT BOTH TERMINALS AFTER 03Z AS WINDS INCREASE TO
35-40 KT WITHIN 2K FT OF THE SURFACE.

EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN MVFR CIGS SUNDAY
NIGHT WITH A COLD FRONTAL PASSAGE. BREEZY SUNDAY AFTERNOON WITH
GUSTS TO 25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL
INTO TUE BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KCHS 251527
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1127 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MESOSCALE UPDATE...LINE OF TSTMS EXTENDING FROM DENMARK SOUTH
THROUGH CLAXTON AND HUGHLAND IS MOVING QUICKLY EAST AND IS ON
TRACK TO MOVE OVER LIBERTY...BRYAN...LONG AND POSSIBLY SOUTHERN
CHATHAM COUNTY WITHIN THE HOUR. INSTABILITY AHEAD OF THE LINE IS
MARGINAL AT BEST.

ACTIVITY IS PROGGED TO CLEAR THE COAST 18-19Z WITH HIGH RES
GUIDANCE SHOWING SIGNIFICANT POST CONVECTION RECOVERY /TEMPS
SOARING INTO THE 80S/ OCCURRING THROUGH 21Z BEFORE ANOTHER LINE OF
TSTMS POTENTIALLY MOVES IN AND AFFECTS AREAS SOUTH OF I-16 LATER
THIS AFTERNOON. THIS IS THE LINE OF TSTMS THAT COULD POSE A MORE
SUBSTANTIAL RISK FOR SEVERE WEATHER SHOULD THE RECOVERY OCCUR. IT
IS UNCLEAR HOW FAR NORTH THIS LINE COULD REACH...BUT STILL THINK
AREAS ALONG/SOUTH OF A METTER-BEAUFORT LINE OF THE BEST
CONDITIONAL PROBABILITIES FOR SEVERE TSTMS LATER TODAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND
SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE
DISTURBANCE. LOWS SHOULD BE IN THE MID TO UPPER 6S ACROSS THE
AREA.

SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL AT KCHS AND KSAV UNTIL CONDITIONS
BEGIN TO DETERIORATE AROUND MIDDAY AS SHOWERS AND THUNDERSTORMS
SPREAD ACROSS THE AREA AS A WARM FRONT LIFTS NORTH. EXPECT MVFR OR
LOWER CONDITIONS TO DEVELOP WITHIN THE SHOWERS AND
THUNDERSTORMS...ROUGHLY IN THE 16-23Z TIME FRAME. THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING STRONG/ERRATIC WINDS...HEAVY RAIN AND
FREQUENT LIGHTNING. EVEN OUTSIDE OF CONVECTION...WINDS WILL BE
BREEZY THIS AFTERNOON WITH GUSTS UPWARDS OF AROUND 20 KT. SOME
SHOWERS COULD LINGER INTO LATE THIS EVENING...BUT VFR CONDITIONS
ARE GENERALLY EXPECTED ONCE THE BULK OF THE CONVECTION MOVES
THROUGH. LINGERING LOW LEVEL MOISTURE COULD PRODUCE SOME MVFR OR
LOWER CEILINGS TOWARD DAYBREAK SUNDAY. LOW LEVEL WIND SHEAR COULD
BE A FACTOR AT BOTH TERMINALS AFTER 03Z AS WINDS INCREASE TO
35-40 KT WITHIN 2K FT OF THE SURFACE.

EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN MVFR CIGS SUNDAY
NIGHT WITH A COLD FRONTAL PASSAGE. BREEZY SUNDAY AFTERNOON WITH
GUSTS TO 25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL
INTO TUE BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KCHS 251527
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1127 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MESOSCALE UPDATE...LINE OF TSTMS EXTENDING FROM DENMARK SOUTH
THROUGH CLAXTON AND HUGHLAND IS MOVING QUICKLY EAST AND IS ON
TRACK TO MOVE OVER LIBERTY...BRYAN...LONG AND POSSIBLY SOUTHERN
CHATHAM COUNTY WITHIN THE HOUR. INSTABILITY AHEAD OF THE LINE IS
MARGINAL AT BEST.

ACTIVITY IS PROGGED TO CLEAR THE COAST 18-19Z WITH HIGH RES
GUIDANCE SHOWING SIGNIFICANT POST CONVECTION RECOVERY /TEMPS
SOARING INTO THE 80S/ OCCURRING THROUGH 21Z BEFORE ANOTHER LINE OF
TSTMS POTENTIALLY MOVES IN AND AFFECTS AREAS SOUTH OF I-16 LATER
THIS AFTERNOON. THIS IS THE LINE OF TSTMS THAT COULD POSE A MORE
SUBSTANTIAL RISK FOR SEVERE WEATHER SHOULD THE RECOVERY OCCUR. IT
IS UNCLEAR HOW FAR NORTH THIS LINE COULD REACH...BUT STILL THINK
AREAS ALONG/SOUTH OF A METTER-BEAUFORT LINE OF THE BEST
CONDITIONAL PROBABILITIES FOR SEVERE TSTMS LATER TODAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND
SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE
DISTURBANCE. LOWS SHOULD BE IN THE MID TO UPPER 6S ACROSS THE
AREA.

SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL AT KCHS AND KSAV UNTIL CONDITIONS
BEGIN TO DETERIORATE AROUND MIDDAY AS SHOWERS AND THUNDERSTORMS
SPREAD ACROSS THE AREA AS A WARM FRONT LIFTS NORTH. EXPECT MVFR OR
LOWER CONDITIONS TO DEVELOP WITHIN THE SHOWERS AND
THUNDERSTORMS...ROUGHLY IN THE 16-23Z TIME FRAME. THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING STRONG/ERRATIC WINDS...HEAVY RAIN AND
FREQUENT LIGHTNING. EVEN OUTSIDE OF CONVECTION...WINDS WILL BE
BREEZY THIS AFTERNOON WITH GUSTS UPWARDS OF AROUND 20 KT. SOME
SHOWERS COULD LINGER INTO LATE THIS EVENING...BUT VFR CONDITIONS
ARE GENERALLY EXPECTED ONCE THE BULK OF THE CONVECTION MOVES
THROUGH. LINGERING LOW LEVEL MOISTURE COULD PRODUCE SOME MVFR OR
LOWER CEILINGS TOWARD DAYBREAK SUNDAY. LOW LEVEL WIND SHEAR COULD
BE A FACTOR AT BOTH TERMINALS AFTER 03Z AS WINDS INCREASE TO
35-40 KT WITHIN 2K FT OF THE SURFACE.

EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN MVFR CIGS SUNDAY
NIGHT WITH A COLD FRONTAL PASSAGE. BREEZY SUNDAY AFTERNOON WITH
GUSTS TO 25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL
INTO TUE BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KGSP 251458
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1058 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
1500 UTC UPDATE...POPS WERE TRIMMED BACK FURTHER BASED ON RADAR
TRENDS FROM WEST TO EAST.

1400 UTC UPDATE...POPS WERE ADJUSTED BASED ON RADAR TRENDS...FAVORING
THE EAST OVER THE WEST. WINDS WERE UPDATED FROM AN EQUALLY WEIGHTED
BLEND OF THE LATEST ADJMAV AND NAM. AREAS OF RAIN INDUCED FOG WERE
UPDATED BASED ON OBSERVATIONS. TEMPERATURE EAST OF KCLT WERE
ADJUSTED SLIGHTLY FOR A BETTER FIT WITH NEIGHBORING OFFICES.

AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...LLVL MOISTURE WILL RAPIDLY INCREASE FROM THE SOUTHWEST
DURING THE MID TO LATE MORNING HOURS...RESULTING IN MVFR CEILINGS
AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO THE AFTERNOON
AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING. BASED ON THE
TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES WILL DEVELOP
DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL HIGHLIGHT THE
22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE EVENING...FORECAST
SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND MODEL CLOUDS ARE
EASILY WITHIN IFR. WINDS THROUGH THIS EVENING WILL REMAIN FROM THE
SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A WELL ORGANIZED
SFC LOW OVER KY/TN. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. HOWEVER...EMBEDDED
THUNDERSTORMS MAY PASS ACROSS THE REGION DURING THE EARLY DAYLIGHT
HOURS. THE DEEP MOISTURE AND FORCING WILL SPREAD SW TO NE...REACHING
KHKY AROUND THE SAME PERIOD AS KCLT. KHKY MAY DEVELOP WINDS FROM THE
EAST-NORTHEAST AROUND SUNRISE...PERSISTING THROUGH THE REST OF THE
TAF PERIOD. ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            15-21Z        21-03Z        03-09Z        09-12Z
KCLT       MED   71%     HIGH  82%     LOW   46%     HIGH  82%
KGSP       HIGH  98%     MED   69%     HIGH  88%     HIGH 100%
KAVL       HIGH  86%     MED   76%     HIGH 100%     HIGH 100%
KHKY       HIGH  87%     MED   77%     HIGH  87%     MED   71%
KGMU       HIGH 100%     MED   72%     HIGH  88%     HIGH 100%
KAND       HIGH  87%     MED   78%     HIGH  97%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.FIRE WEATHER...
THE PLANNING FORECAST WILL BE UPDATED FOR LOWER TRANSPORT WINDS
UNDER LIMITED MIXING HEIGHTS AS RAIN MOISTENS THE ATMOSPHERE. SMOKE
MANAGEMENT PARAMETERS HAVE BEEN ADJUSTED ACCORDINGLY.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...JAT/NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED
FIRE WEATHER...JAT



000
FXUS62 KGSP 251458
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1058 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
1500 UTC UPDATE...POPS WERE TRIMMED BACK FURTHER BASED ON RADAR
TRENDS FROM WEST TO EAST.

1400 UTC UPDATE...POPS WERE ADJUSTED BASED ON RADAR TRENDS...FAVORING
THE EAST OVER THE WEST. WINDS WERE UPDATED FROM AN EQUALLY WEIGHTED
BLEND OF THE LATEST ADJMAV AND NAM. AREAS OF RAIN INDUCED FOG WERE
UPDATED BASED ON OBSERVATIONS. TEMPERATURE EAST OF KCLT WERE
ADJUSTED SLIGHTLY FOR A BETTER FIT WITH NEIGHBORING OFFICES.

AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...LLVL MOISTURE WILL RAPIDLY INCREASE FROM THE SOUTHWEST
DURING THE MID TO LATE MORNING HOURS...RESULTING IN MVFR CEILINGS
AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO THE AFTERNOON
AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING. BASED ON THE
TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES WILL DEVELOP
DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL HIGHLIGHT THE
22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE EVENING...FORECAST
SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND MODEL CLOUDS ARE
EASILY WITHIN IFR. WINDS THROUGH THIS EVENING WILL REMAIN FROM THE
SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A WELL ORGANIZED
SFC LOW OVER KY/TN. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. HOWEVER...EMBEDDED
THUNDERSTORMS MAY PASS ACROSS THE REGION DURING THE EARLY DAYLIGHT
HOURS. THE DEEP MOISTURE AND FORCING WILL SPREAD SW TO NE...REACHING
KHKY AROUND THE SAME PERIOD AS KCLT. KHKY MAY DEVELOP WINDS FROM THE
EAST-NORTHEAST AROUND SUNRISE...PERSISTING THROUGH THE REST OF THE
TAF PERIOD. ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            15-21Z        21-03Z        03-09Z        09-12Z
KCLT       MED   71%     HIGH  82%     LOW   46%     HIGH  82%
KGSP       HIGH  98%     MED   69%     HIGH  88%     HIGH 100%
KAVL       HIGH  86%     MED   76%     HIGH 100%     HIGH 100%
KHKY       HIGH  87%     MED   77%     HIGH  87%     MED   71%
KGMU       HIGH 100%     MED   72%     HIGH  88%     HIGH 100%
KAND       HIGH  87%     MED   78%     HIGH  97%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.FIRE WEATHER...
THE PLANNING FORECAST WILL BE UPDATED FOR LOWER TRANSPORT WINDS
UNDER LIMITED MIXING HEIGHTS AS RAIN MOISTENS THE ATMOSPHERE. SMOKE
MANAGEMENT PARAMETERS HAVE BEEN ADJUSTED ACCORDINGLY.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...JAT/NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED
FIRE WEATHER...JAT




000
FXUS62 KGSP 251458
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1058 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
1500 UTC UPDATE...POPS WERE TRIMMED BACK FURTHER BASED ON RADAR
TRENDS FROM WEST TO EAST.

1400 UTC UPDATE...POPS WERE ADJUSTED BASED ON RADAR TRENDS...FAVORING
THE EAST OVER THE WEST. WINDS WERE UPDATED FROM AN EQUALLY WEIGHTED
BLEND OF THE LATEST ADJMAV AND NAM. AREAS OF RAIN INDUCED FOG WERE
UPDATED BASED ON OBSERVATIONS. TEMPERATURE EAST OF KCLT WERE
ADJUSTED SLIGHTLY FOR A BETTER FIT WITH NEIGHBORING OFFICES.

AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...LLVL MOISTURE WILL RAPIDLY INCREASE FROM THE SOUTHWEST
DURING THE MID TO LATE MORNING HOURS...RESULTING IN MVFR CEILINGS
AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO THE AFTERNOON
AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING. BASED ON THE
TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES WILL DEVELOP
DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL HIGHLIGHT THE
22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE EVENING...FORECAST
SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND MODEL CLOUDS ARE
EASILY WITHIN IFR. WINDS THROUGH THIS EVENING WILL REMAIN FROM THE
SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A WELL ORGANIZED
SFC LOW OVER KY/TN. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. HOWEVER...EMBEDDED
THUNDERSTORMS MAY PASS ACROSS THE REGION DURING THE EARLY DAYLIGHT
HOURS. THE DEEP MOISTURE AND FORCING WILL SPREAD SW TO NE...REACHING
KHKY AROUND THE SAME PERIOD AS KCLT. KHKY MAY DEVELOP WINDS FROM THE
EAST-NORTHEAST AROUND SUNRISE...PERSISTING THROUGH THE REST OF THE
TAF PERIOD. ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            15-21Z        21-03Z        03-09Z        09-12Z
KCLT       MED   71%     HIGH  82%     LOW   46%     HIGH  82%
KGSP       HIGH  98%     MED   69%     HIGH  88%     HIGH 100%
KAVL       HIGH  86%     MED   76%     HIGH 100%     HIGH 100%
KHKY       HIGH  87%     MED   77%     HIGH  87%     MED   71%
KGMU       HIGH 100%     MED   72%     HIGH  88%     HIGH 100%
KAND       HIGH  87%     MED   78%     HIGH  97%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.FIRE WEATHER...
THE PLANNING FORECAST WILL BE UPDATED FOR LOWER TRANSPORT WINDS
UNDER LIMITED MIXING HEIGHTS AS RAIN MOISTENS THE ATMOSPHERE. SMOKE
MANAGEMENT PARAMETERS HAVE BEEN ADJUSTED ACCORDINGLY.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...JAT/NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED
FIRE WEATHER...JAT



000
FXUS62 KGSP 251458
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1058 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
1500 UTC UPDATE...POPS WERE TRIMMED BACK FURTHER BASED ON RADAR
TRENDS FROM WEST TO EAST.

1400 UTC UPDATE...POPS WERE ADJUSTED BASED ON RADAR TRENDS...FAVORING
THE EAST OVER THE WEST. WINDS WERE UPDATED FROM AN EQUALLY WEIGHTED
BLEND OF THE LATEST ADJMAV AND NAM. AREAS OF RAIN INDUCED FOG WERE
UPDATED BASED ON OBSERVATIONS. TEMPERATURE EAST OF KCLT WERE
ADJUSTED SLIGHTLY FOR A BETTER FIT WITH NEIGHBORING OFFICES.

AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...LLVL MOISTURE WILL RAPIDLY INCREASE FROM THE SOUTHWEST
DURING THE MID TO LATE MORNING HOURS...RESULTING IN MVFR CEILINGS
AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO THE AFTERNOON
AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING. BASED ON THE
TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES WILL DEVELOP
DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL HIGHLIGHT THE
22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE EVENING...FORECAST
SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND MODEL CLOUDS ARE
EASILY WITHIN IFR. WINDS THROUGH THIS EVENING WILL REMAIN FROM THE
SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A WELL ORGANIZED
SFC LOW OVER KY/TN. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. HOWEVER...EMBEDDED
THUNDERSTORMS MAY PASS ACROSS THE REGION DURING THE EARLY DAYLIGHT
HOURS. THE DEEP MOISTURE AND FORCING WILL SPREAD SW TO NE...REACHING
KHKY AROUND THE SAME PERIOD AS KCLT. KHKY MAY DEVELOP WINDS FROM THE
EAST-NORTHEAST AROUND SUNRISE...PERSISTING THROUGH THE REST OF THE
TAF PERIOD. ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            15-21Z        21-03Z        03-09Z        09-12Z
KCLT       MED   71%     HIGH  82%     LOW   46%     HIGH  82%
KGSP       HIGH  98%     MED   69%     HIGH  88%     HIGH 100%
KAVL       HIGH  86%     MED   76%     HIGH 100%     HIGH 100%
KHKY       HIGH  87%     MED   77%     HIGH  87%     MED   71%
KGMU       HIGH 100%     MED   72%     HIGH  88%     HIGH 100%
KAND       HIGH  87%     MED   78%     HIGH  97%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.FIRE WEATHER...
THE PLANNING FORECAST WILL BE UPDATED FOR LOWER TRANSPORT WINDS
UNDER LIMITED MIXING HEIGHTS AS RAIN MOISTENS THE ATMOSPHERE. SMOKE
MANAGEMENT PARAMETERS HAVE BEEN ADJUSTED ACCORDINGLY.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...JAT/NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED
FIRE WEATHER...JAT




000
FXUS62 KCHS 251400
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
957 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN ILL-DEFINED WARM FRONT IS MOVING QUICKLY NORTH. BIG ISSUE
TODAY IS WHETHER SEVERE WEATHER WILL OCCUR OR NOT. A LARGE AREA OF
SHOWERS/TSTMS IS ALREADY APPROACHING THE FAR WESTERN PORTIONS OF THE
FORECAST AREA...WHICH WILL SPREAD EAST TO THE COAST THROUGH THE LATE
MORNING AND EARLY AFTERNOON. THE BULK OF THIS ACTIVITY WILL
GENERALLY REMAIN ALONG/NORTH OF THE I-16 CORRIDOR AND WILL TEND
STABILIZE PARTS OF THE FORECAST AREA FOR A GOOD PORTION OF THE DAY.
IT IS THEREFORE VERY UNCERTAIN ON WHETHER ENOUGH RECOVERY WILL OCCUR
IN THE WAKE OF THIS ACTIVITY TO SUPPORT A POTENTIAL QLCS MID-LATE
AFTERNOON AS SUGGESTED BY THE H3R...4KM NSSL WRF AND THE HIGH RES
ARW-EAST MODELS. IT IS HARD TO IGNORE THE TRENDS NOTED IN ALL THREE
HIGH RESOLUTION MODELS...SO CONVECTIVE AND STABILITY TRENDS ARE
BEING WATCHED CAREFULLY.

ATTM IT APPEARS THE GREATER CHANCE FOR SIGNIFICANT DESTABILIZATION
WILL BE CONFINED TO AREAS SOUTH OF A METTER-BEAUFORT LINE...WHICH
INCLUDES THE SAVANNAH METRO AREA. THIS AREA WILL HAVE THE GREATER
PROBABILITIES FOR DAMAGING WINDS AND POSSIBLY A FEW TORNADOES WHERE
0-1KM EHI AND SR-HELICITY ARE FORECAST TO RISE TO 1.5-2 UNITS AND
200-400 M2/S2 RESPECTIVELY WITH SHERBS3 VALUES INCREASING TO 1.0-1.3
UNITS. MODIFIED SOUNDING AT METTER AND HINESVILLE BOTH SUPPORT
SBCAPE 2000 J/KG...MLCAPE 1500 J/KG...LIFTED INDEX OF -6C WITH A
SHOWALTER OF -2C...ASSUMING ENOUGH HEATING OCCURS LATER TODAY. BULK
SHEAR IS SUPPORTIVE OF A FEW SUPERCELLS WITH VALUES 55-65 KT.

FOR THE LATE MORNING UPDATE...
* MODIFIED HOURLY POPS TO MATCH CURRENT RADAR AND SHORT TERM MODEL
  TRENDS. MAX POPS ARE 80-100 PERCENT THROUGH LATE AFTERNOON.
* ADJUSTED HOURLY TEMPERATURES SLIGHTLY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND
SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE
DISTURBANCE. LOWS SHOULD BE IN THE MID TO UPPER 6S ACROSS THE
AREA.

SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL AT KCHS AND KSAV UNTIL CONDITIONS
BEGIN TO DETERIORATE AROUND MIDDAY AS SHOWERS AND THUNDERSTORMS
SPREAD ACROSS THE AREA AS A WARM FRONT LIFTS NORTH. EXPECT MVFR OR
LOWER CONDITIONS TO DEVELOP WITHIN THE SHOWERS AND
THUNDERSTORMS...ROUGHLY IN THE 16-23Z TIME FRAME. THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING STRONG/ERRATIC WINDS...HEAVY RAIN AND
FREQUENT LIGHTNING. EVEN OUTSIDE OF CONVECTION...WINDS WILL BE
BREEZY THIS AFTERNOON WITH GUSTS UPWARDS OF AROUND 20 KT. SOME
SHOWERS COULD LINGER INTO LATE THIS EVENING...BUT VFR CONDITIONS
ARE GENERALLY EXPECTED ONCE THE BULK OF THE CONVECTION MOVES
THROUGH. LINGERING LOW LEVEL MOISTURE COULD PRODUCE SOME MVFR OR
LOWER CEILINGS TOWARD DAYBREAK SUNDAY. LOW LEVEL WIND SHEAR COULD
BE A FACTOR AT BOTH TERMINALS AFTER 03Z AS WINDS INCREASE TO
35-40 KT WITHIN 2K FT OF THE SURFACE.

EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN MVFR CIGS SUNDAY
NIGHT WITH A COLD FRONTAL PASSAGE. BREEZY SUNDAY AFTERNOON WITH
GUSTS TO 25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL
INTO TUE BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KGSP 251358
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
958 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
1400 UTC UPDATE...POPS WERE ADJUSTED BASED ON RADAR TRENDS...FAVORING
THE EAST OVER THE WEST. WINDS WERE UPDATED FROM AN EQUALLY WEIGHTED
BLEND OF THE LATEST ADJMAV AND NAM. AREAS OF RAIN INDUCED FOG WERE
UPDATED BASED ON OBSERVATIONS. TEMPERATURE EAST OF KCLT WERE
ADJUSTED SLIGHTLY FOR A BETTER FIT WITH NEIGHBORING OFFICES.

AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...LLVL MOISTURE WILL RAPIDLY INCREASE FROM THE SOUTHWEST
DURING THE MID TO LATE MORNING HOURS...RESULTING IN MVFR CEILINGS
AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO THE AFTERNOON
AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING. BASED ON THE
TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES WILL DEVELOP
DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL HIGHLIGHT THE
22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE EVENING...FORECAST
SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND MODEL CLOUDS ARE
EASILY WITHIN IFR. WINDS THROUGH THIS EVENING WILL REMAIN FROM THE
SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A WELL ORGANIZED
SFC LOW OVER KY/TN. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. HOWEVER...EMBEDDED
THUNDERSTORMS MAY PASS ACROSS THE REGION DURING THE EARLY DAYLIGHT
HOURS. THE DEEP MOISTURE AND FORCING WILL SPREAD SW TO NE...REACHING
KHKY AROUND THE SAME PERIOD AS KCLT. KHKY MAY DEVELOP WINDS FROM THE
EAST-NORTHEAST AROUND SUNRISE...PERSISTING THROUGH THE REST OF THE
TAF PERIOD. ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            14-20Z        20-02Z        02-08Z        08-12Z
KCLT       MED   70%     HIGH  87%     LOW   49%     HIGH  87%
KGSP       HIGH  92%     HIGH  81%     HIGH  84%     HIGH 100%
KAVL       MED   68%     MED   75%     HIGH 100%     HIGH 100%
KHKY       MED   78%     MED   79%     HIGH  85%     HIGH  87%
KGMU       HIGH  97%     MED   77%     HIGH  85%     HIGH  97%
KAND       MED   76%     HIGH  83%     HIGH  96%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.FIRE WEATHER...
THE PLANNING FORECAST WILL BE UPDATED FOR LOWER TRANSPORT WINDS
UNDER LIMITED MIXING HEIGHTS AS RAIN MOISTENS THE ATMOSPHERE. SMOKE
MANAGEMENT PARAMETERS HAVE BEEN ADJUSTED ACCORDINGLY.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...JAT/NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED
FIRE WEATHER...JAT



000
FXUS62 KGSP 251358
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
958 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
1400 UTC UPDATE...POPS WERE ADJUSTED BASED ON RADAR TRENDS...FAVORING
THE EAST OVER THE WEST. WINDS WERE UPDATED FROM AN EQUALLY WEIGHTED
BLEND OF THE LATEST ADJMAV AND NAM. AREAS OF RAIN INDUCED FOG WERE
UPDATED BASED ON OBSERVATIONS. TEMPERATURE EAST OF KCLT WERE
ADJUSTED SLIGHTLY FOR A BETTER FIT WITH NEIGHBORING OFFICES.

AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...LLVL MOISTURE WILL RAPIDLY INCREASE FROM THE SOUTHWEST
DURING THE MID TO LATE MORNING HOURS...RESULTING IN MVFR CEILINGS
AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO THE AFTERNOON
AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING. BASED ON THE
TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES WILL DEVELOP
DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL HIGHLIGHT THE
22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE EVENING...FORECAST
SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND MODEL CLOUDS ARE
EASILY WITHIN IFR. WINDS THROUGH THIS EVENING WILL REMAIN FROM THE
SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A WELL ORGANIZED
SFC LOW OVER KY/TN. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. HOWEVER...EMBEDDED
THUNDERSTORMS MAY PASS ACROSS THE REGION DURING THE EARLY DAYLIGHT
HOURS. THE DEEP MOISTURE AND FORCING WILL SPREAD SW TO NE...REACHING
KHKY AROUND THE SAME PERIOD AS KCLT. KHKY MAY DEVELOP WINDS FROM THE
EAST-NORTHEAST AROUND SUNRISE...PERSISTING THROUGH THE REST OF THE
TAF PERIOD. ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            14-20Z        20-02Z        02-08Z        08-12Z
KCLT       MED   70%     HIGH  87%     LOW   49%     HIGH  87%
KGSP       HIGH  92%     HIGH  81%     HIGH  84%     HIGH 100%
KAVL       MED   68%     MED   75%     HIGH 100%     HIGH 100%
KHKY       MED   78%     MED   79%     HIGH  85%     HIGH  87%
KGMU       HIGH  97%     MED   77%     HIGH  85%     HIGH  97%
KAND       MED   76%     HIGH  83%     HIGH  96%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.FIRE WEATHER...
THE PLANNING FORECAST WILL BE UPDATED FOR LOWER TRANSPORT WINDS
UNDER LIMITED MIXING HEIGHTS AS RAIN MOISTENS THE ATMOSPHERE. SMOKE
MANAGEMENT PARAMETERS HAVE BEEN ADJUSTED ACCORDINGLY.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...JAT/NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED
FIRE WEATHER...JAT




000
FXUS62 KCHS 251357
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
957 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN ILL-DEFINED WARM FRONT IS MOVING QUICKLY NORTH. BIG ISSUE
TODAY IS WHETHER SEVERE WEATHER WILL OCCUR OR NOT. A LARGE AREA OF
SHOWERS/TSTMS ARE ALREADY APPROACHING THE FAR WESTERN PORTIONS OF
THE FORECAST AREA...WHICH WILL SPREAD EAST TO THE COAST THROUGH
THE LATE MORNING AND EARLY AFTERNOON. THE BULK OF THIS ACTIVITY
WILL GENERALLY REMAIN ALONG/NORTH OF THE I-16 CORRIDOR AND WILL
TEND STABILIZE PARTS OF THE FORECAST AREA FOR A GOOD PORTION OF
THE DAY. IT IS THEREFORE VERY UNCERTAIN ON WHETHER ENOUGH RECOVERY
WILL OCCUR IN THE WAKE OF THIS ACTIVITY TO SUPPORT A POTENTIAL
QLCS MID-LATE AFTERNOON AS SUGGESTED BY THE H3R...4KM NSSL WRF AND
THE HIGH RES ARW-EAST MODELS. IT IS HARD TO IGNORE THE TRENDS
NOTED IN ALL THREE HIGH RESOLUTION MODELS...SO CONVECTIVE AND
STABILITY TRENDS ARE BEING WATCHED CAREFULLY.

ATTM IT APPEARS THE GREATER CHANCE FOR SIGNIFICANT DESTABILIZATIONWILL
BE CONFINED TO AREAS SOUTH OF A METTER-BEAUFORT LINE...WHICH
INCLUDES THE SAVANNAH METRO AREA. THIS AREA WILL HAVE THE GREATER
PROBABILITIES FOR DAMAGING WINDS AND POSSIBLY A FEW TORNADOES
WHERE 0-1KM EHI AND SR-HELICITY ARE FORECAST TO RISE TO 1.5-2
UNITS AND 200-400 M2/S2 RESPECTIVELY WITH SHERBS3 VALUES
INCREASING TO 1.0-1.3 UNITS. MODIFIED SOUNDING AT METTER AND
HINESVILLE BOTH SUPPORT SBCAPE 2000 J/KG...MLCAPE 1500
J/KG...LIFTED INDEX OF -6C WITH A SHOWALTER OF -2C...ASSUMING
ENOUGH HEATING OCCURS LATER TODAY. BULK SHEAR IS SUPPORTIVE OF A
FEW SUPERCELLS WITH VALUES 55-65 KT.

FOR THE LATE MORNING UPDATE...
* MODIFIED HOURLY POPS TO MATCH CURRENT RADAR AND SHORT TERM MODEL
  TRENDS. MAX POPS ARE 80-100 PERCENT THROUGH LATE AFTERNOON.
* ADJUSTED HOURLY TEMPERATURES SLIGHTLY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND
SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE
DISTURBANCE. LOWS SHOULD BE IN THE MID TO UPPER 6S ACROSS THE
AREA.

SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL AT KCHS AND KSAV UNTIL CONDITIONS
BEGIN TO DETERIORATE AROUND MIDDAY AS SHOWERS AND THUNDERSTORMS
SPREAD ACROSS THE AREA AS A WARM FRONT LIFTS NORTH. EXPECT MVFR OR
LOWER CONDITIONS TO DEVELOP WITHIN THE SHOWERS AND
THUNDERSTORMS...ROUGHLY IN THE 16-23Z TIME FRAME. THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING STRONG/ERRATIC WINDS...HEAVY RAIN AND
FREQUENT LIGHTNING. EVEN OUTSIDE OF CONVECTION...WINDS WILL BE
BREEZY THIS AFTERNOON WITH GUSTS UPWARDS OF AROUND 20 KT. SOME
SHOWERS COULD LINGER INTO LATE THIS EVENING...BUT VFR CONDITIONS
ARE GENERALLY EXPECTED ONCE THE BULK OF THE CONVECTION MOVES
THROUGH. LINGERING LOW LEVEL MOISTURE COULD PRODUCE SOME MVFR OR
LOWER CEILINGS TOWARD DAYBREAK SUNDAY. LOW LEVEL WIND SHEAR COULD
BE A FACTOR AT BOTH TERMINALS AFTER 03Z AS WINDS INCREASE TO
35-40 KT WITHIN 2K FT OF THE SURFACE.

EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN MVFR CIGS SUNDAY
NIGHT WITH A COLD FRONTAL PASSAGE. BREEZY SUNDAY AFTERNOON WITH
GUSTS TO 25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL
INTO TUE BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST



000
FXUS62 KCHS 251357
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
957 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN ILL-DEFINED WARM FRONT IS MOVING QUICKLY NORTH. BIG ISSUE
TODAY IS WHETHER SEVERE WEATHER WILL OCCUR OR NOT. A LARGE AREA OF
SHOWERS/TSTMS ARE ALREADY APPROACHING THE FAR WESTERN PORTIONS OF
THE FORECAST AREA...WHICH WILL SPREAD EAST TO THE COAST THROUGH
THE LATE MORNING AND EARLY AFTERNOON. THE BULK OF THIS ACTIVITY
WILL GENERALLY REMAIN ALONG/NORTH OF THE I-16 CORRIDOR AND WILL
TEND STABILIZE PARTS OF THE FORECAST AREA FOR A GOOD PORTION OF
THE DAY. IT IS THEREFORE VERY UNCERTAIN ON WHETHER ENOUGH RECOVERY
WILL OCCUR IN THE WAKE OF THIS ACTIVITY TO SUPPORT A POTENTIAL
QLCS MID-LATE AFTERNOON AS SUGGESTED BY THE H3R...4KM NSSL WRF AND
THE HIGH RES ARW-EAST MODELS. IT IS HARD TO IGNORE THE TRENDS
NOTED IN ALL THREE HIGH RESOLUTION MODELS...SO CONVECTIVE AND
STABILITY TRENDS ARE BEING WATCHED CAREFULLY.

ATTM IT APPEARS THE GREATER CHANCE FOR SIGNIFICANT DESTABILIZATIONWILL
BE CONFINED TO AREAS SOUTH OF A METTER-BEAUFORT LINE...WHICH
INCLUDES THE SAVANNAH METRO AREA. THIS AREA WILL HAVE THE GREATER
PROBABILITIES FOR DAMAGING WINDS AND POSSIBLY A FEW TORNADOES
WHERE 0-1KM EHI AND SR-HELICITY ARE FORECAST TO RISE TO 1.5-2
UNITS AND 200-400 M2/S2 RESPECTIVELY WITH SHERBS3 VALUES
INCREASING TO 1.0-1.3 UNITS. MODIFIED SOUNDING AT METTER AND
HINESVILLE BOTH SUPPORT SBCAPE 2000 J/KG...MLCAPE 1500
J/KG...LIFTED INDEX OF -6C WITH A SHOWALTER OF -2C...ASSUMING
ENOUGH HEATING OCCURS LATER TODAY. BULK SHEAR IS SUPPORTIVE OF A
FEW SUPERCELLS WITH VALUES 55-65 KT.

FOR THE LATE MORNING UPDATE...
* MODIFIED HOURLY POPS TO MATCH CURRENT RADAR AND SHORT TERM MODEL
  TRENDS. MAX POPS ARE 80-100 PERCENT THROUGH LATE AFTERNOON.
* ADJUSTED HOURLY TEMPERATURES SLIGHTLY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND
SUBSIDENCE DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE
DISTURBANCE. LOWS SHOULD BE IN THE MID TO UPPER 6S ACROSS THE
AREA.

SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL AT KCHS AND KSAV UNTIL CONDITIONS
BEGIN TO DETERIORATE AROUND MIDDAY AS SHOWERS AND THUNDERSTORMS
SPREAD ACROSS THE AREA AS A WARM FRONT LIFTS NORTH. EXPECT MVFR OR
LOWER CONDITIONS TO DEVELOP WITHIN THE SHOWERS AND
THUNDERSTORMS...ROUGHLY IN THE 16-23Z TIME FRAME. THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING STRONG/ERRATIC WINDS...HEAVY RAIN AND
FREQUENT LIGHTNING. EVEN OUTSIDE OF CONVECTION...WINDS WILL BE
BREEZY THIS AFTERNOON WITH GUSTS UPWARDS OF AROUND 20 KT. SOME
SHOWERS COULD LINGER INTO LATE THIS EVENING...BUT VFR CONDITIONS
ARE GENERALLY EXPECTED ONCE THE BULK OF THE CONVECTION MOVES
THROUGH. LINGERING LOW LEVEL MOISTURE COULD PRODUCE SOME MVFR OR
LOWER CEILINGS TOWARD DAYBREAK SUNDAY. LOW LEVEL WIND SHEAR COULD
BE A FACTOR AT BOTH TERMINALS AFTER 03Z AS WINDS INCREASE TO
35-40 KT WITHIN 2K FT OF THE SURFACE.

EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN MVFR CIGS SUNDAY
NIGHT WITH A COLD FRONTAL PASSAGE. BREEZY SUNDAY AFTERNOON WITH
GUSTS TO 25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL
INTO TUE BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

ST




000
FXUS62 KCAE 251147
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
747 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT LIFTING NORTHWARD INTO THE AREA TODAY WILL BE THE FOCUS
FOR SHOWERS AND SOME THUNDERSTORMS TODAY. DRIER WEATHER RETURNS FOR
SUNDAY AS A COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /THROUGH TONIGHT/...
A WARM FRONT WILL LIFT NORTHWARD INTO THE AREA TODAY. PRECIPITABLE
WATER VALUES RAPIDLY INCREASE TO OVER ONE INCH BY SUNRISE...AND
NEAR 1.80 INCHES FOR THIS AFTERNOON. ISENTROPIC LIFT AND WARM
ADVECTION THIS MORNING WILL BRING WIDESPREAD SHOWERS TO THE AREA.
CATEGORICAL POPS LOOK IN ORDER FOR THIS MORNING. AS THE WARM FRONT
LIFTS NORTH THE AIRMASS WILL DESTABILIZE WITH INCREASING SPEED AND
DIRECTIONAL SHEAR...WHICH SUPPORT ROTATION STORMS. INSTABILITY
WILL BE LIMITED UNTIL LATE AFTERNOON AND TONIGHT WHEN LI VALUES
REACH MINUS 4C TO MINUS 5C AND CAPE AROUND 1500 J/KG.

POTENTIAL FOR SEVERE STORMS WITH TWO WAVES POSSIBLE. THE FIRST
IS ASSOCIATED WITH AN MCS COMPLEX PUSHING EASTWARD TO ARRIVE
AROUND MIDDAY INTO EARLY AFTERNOON...WITH FAVORABLE JET STREAM
DYNAMICS. ANOTHER ROUND EXPECTED TO ARRIVE THIS EVENING WHEN DRIER
AIR ALOFT REACHES THE AREA...COMBINED WITH THE BEST INSTABILITY.
SPC HAS OUR ENTIRE AREA IN A SLIGHT RISK WITH AN AREA OF ENHANCED
RISK ACROSS TN/KY.

TEMPERATURES TODAY WILL BE LIMITED BY THE CLOUDS AND RAINFALL FOR
MUCH OF THE DAY BUT THERE IS SOME UNCERTAINTY ABOUT SOME POSSIBLE
RECOVERY LATE. WE SHOULD SEE A GRADIENT IN TEMPS FROM THE 60S
NORTH TO 70S SOUTH.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS NOTED ON SUNDAY
BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO WILL
CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
MEDIUM RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. LATEST GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE
WEST FRIDAY. TEMPERATURES GENERALLY AT OR JUST BELOW NORMAL
THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
LIGHT RAIN HAS OVERSPREAD THE TERMINALS AS A WARM FRONT DEVELOPS AND
LIFTS NORTHWARD THROUGH THE AREA.  MOS GUIDANCE BRINGS MVFR CIGS
WITH POSSIBLE IFR CIGS DURING THE 14Z-22Z TIME FRAME WITH STEADY
RAIN AND EMBEDDED CONVECTION THAT IS CURRENTLY MOVING EAST ACROSS
GEORGIA. CONFIDENCE NOT THAT HIGH DURING THE 12-18Z TIMEFRAME FOR
WIDESPREAD MVFR BASED OFF OF CURRENT AREA OBS AND UPSTREAM OBS.
HAVE CONTINUED LOW END VFR...WITH BRIEF MVFR IN HEAVIER
SHOWERS...THROUGH 18Z...THEN DROP CEILINGS INTO MVFR/IFR AFTER 18Z.
WILL INTRODUCE TSRA AT AGS/DNL/OGB FROM 14Z-17Z AS THESE
TERMINALS ARE MOST LIKELY TO BE AFFECTED WHILE LOWER CONFIDENCE AT
CAE/CUB WILL PRECLUDE IT FROM THE FORECAST. LIGHT SOUTHEAST TO
SOUTHERLY WINDS EXPECTED TODAY UNTIL THE WARM FRONT LIFTS THROUGH
AND THEN WINDS BECOME MORE SOUTHWESTERLY THIS EVENING. CHANCES FOR
ADDITIONAL CONVECTION THIS EVENING BUT IT SHOULD BE MORE SCATTERED
IN NATURE WITH MUCH LESS CERTAINTY IN TIMING AND LOCATION TO
POSSIBLY IMPACT TERMINALS.

LOW-LEVEL WIND SHEAR MAY BE AN ISSUE BEFORE WARM FRONTAL PASSAGE.

EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SUNDAY.
NO SIGNIFICANT IMPACTS EXPECTED MONDAY AND TUESDAY. AN APPROACHING
WARM FRONT MAY RESULT IN WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCAE 251147
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
747 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT LIFTING NORTHWARD INTO THE AREA TODAY WILL BE THE FOCUS
FOR SHOWERS AND SOME THUNDERSTORMS TODAY. DRIER WEATHER RETURNS FOR
SUNDAY AS A COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /THROUGH TONIGHT/...
A WARM FRONT WILL LIFT NORTHWARD INTO THE AREA TODAY. PRECIPITABLE
WATER VALUES RAPIDLY INCREASE TO OVER ONE INCH BY SUNRISE...AND
NEAR 1.80 INCHES FOR THIS AFTERNOON. ISENTROPIC LIFT AND WARM
ADVECTION THIS MORNING WILL BRING WIDESPREAD SHOWERS TO THE AREA.
CATEGORICAL POPS LOOK IN ORDER FOR THIS MORNING. AS THE WARM FRONT
LIFTS NORTH THE AIRMASS WILL DESTABILIZE WITH INCREASING SPEED AND
DIRECTIONAL SHEAR...WHICH SUPPORT ROTATION STORMS. INSTABILITY
WILL BE LIMITED UNTIL LATE AFTERNOON AND TONIGHT WHEN LI VALUES
REACH MINUS 4C TO MINUS 5C AND CAPE AROUND 1500 J/KG.

POTENTIAL FOR SEVERE STORMS WITH TWO WAVES POSSIBLE. THE FIRST
IS ASSOCIATED WITH AN MCS COMPLEX PUSHING EASTWARD TO ARRIVE
AROUND MIDDAY INTO EARLY AFTERNOON...WITH FAVORABLE JET STREAM
DYNAMICS. ANOTHER ROUND EXPECTED TO ARRIVE THIS EVENING WHEN DRIER
AIR ALOFT REACHES THE AREA...COMBINED WITH THE BEST INSTABILITY.
SPC HAS OUR ENTIRE AREA IN A SLIGHT RISK WITH AN AREA OF ENHANCED
RISK ACROSS TN/KY.

TEMPERATURES TODAY WILL BE LIMITED BY THE CLOUDS AND RAINFALL FOR
MUCH OF THE DAY BUT THERE IS SOME UNCERTAINTY ABOUT SOME POSSIBLE
RECOVERY LATE. WE SHOULD SEE A GRADIENT IN TEMPS FROM THE 60S
NORTH TO 70S SOUTH.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS NOTED ON SUNDAY
BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO WILL
CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
MEDIUM RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. LATEST GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE
WEST FRIDAY. TEMPERATURES GENERALLY AT OR JUST BELOW NORMAL
THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
LIGHT RAIN HAS OVERSPREAD THE TERMINALS AS A WARM FRONT DEVELOPS AND
LIFTS NORTHWARD THROUGH THE AREA.  MOS GUIDANCE BRINGS MVFR CIGS
WITH POSSIBLE IFR CIGS DURING THE 14Z-22Z TIME FRAME WITH STEADY
RAIN AND EMBEDDED CONVECTION THAT IS CURRENTLY MOVING EAST ACROSS
GEORGIA. CONFIDENCE NOT THAT HIGH DURING THE 12-18Z TIMEFRAME FOR
WIDESPREAD MVFR BASED OFF OF CURRENT AREA OBS AND UPSTREAM OBS.
HAVE CONTINUED LOW END VFR...WITH BRIEF MVFR IN HEAVIER
SHOWERS...THROUGH 18Z...THEN DROP CEILINGS INTO MVFR/IFR AFTER 18Z.
WILL INTRODUCE TSRA AT AGS/DNL/OGB FROM 14Z-17Z AS THESE
TERMINALS ARE MOST LIKELY TO BE AFFECTED WHILE LOWER CONFIDENCE AT
CAE/CUB WILL PRECLUDE IT FROM THE FORECAST. LIGHT SOUTHEAST TO
SOUTHERLY WINDS EXPECTED TODAY UNTIL THE WARM FRONT LIFTS THROUGH
AND THEN WINDS BECOME MORE SOUTHWESTERLY THIS EVENING. CHANCES FOR
ADDITIONAL CONVECTION THIS EVENING BUT IT SHOULD BE MORE SCATTERED
IN NATURE WITH MUCH LESS CERTAINTY IN TIMING AND LOCATION TO
POSSIBLY IMPACT TERMINALS.

LOW-LEVEL WIND SHEAR MAY BE AN ISSUE BEFORE WARM FRONTAL PASSAGE.

EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS POSSIBLE SUNDAY.
NO SIGNIFICANT IMPACTS EXPECTED MONDAY AND TUESDAY. AN APPROACHING
WARM FRONT MAY RESULT IN WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KCHS 251145
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
745 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...A RATHER ILL-DEFINED WARM FRONT WILL LIFT NORTH OF THE
AREA THIS MORNING AS HIGH PRESSURE OVER THE WESTERN ATLANTIC
CONTINUES TO SHIFT FARTHER FROM THE COAST. TEMPERATURE RISES MAY
BE HELD BACK BY SIGNIFICANT CLOUD COVER TODAY...BUT WITH STRONG
WARM AIR ADVECTION TAKING PLACE STILL EXPECT TO SEE HIGHS RANGING
FROM THE MID AND UPPER 70S ACROSS SOUTHEAST SOUTH CAROLINA AND
LOWER 80S ACROSS SOUTHEAST GEORGIA. BREEZY CONDITIONS ARE ALSO
EXPECTED THIS AFTERNOON.

THE CHARACTER/TIMING OF CONVECTION IS VERY DIFFICULT TO PIN DOWN
TODAY GIVEN VARYING MODEL SOLUTIONS. INITIALLY...SOME
PATCHY LIGHT RAIN SHOWERS COULD OCCUR ACROSS PARTS OF SOUTHEAST
SOUTH CAROLINA THROUGH MID-MORNING ONCE THE LOWER LEVELS OF THE
ATMOSPHERE MOISTEN DUE TO ISENTROPIC ASCENT ASSOCIATED WITH THE
WARM FRONT. THIS AREA OF OVERRUNNING PRECIPITATION WILL LIFT
OUT WITH THE WARM FRONT...THEN THE REMNANTS OF A MESOSCALE
CONVECTIVE COMPLEX /MCS/ SHOULD MOVE INTO THE AREA LATE THIS
MORNING AND CONTINUE TOWARD THE COAST THROUGH EARLY THIS
AFTERNOON WITH RAINFALL PROBABILITIES REACHING 80-100 PERCENT.
HIGH RESOLUTION MESOSCALE MODELS THEN SHOW ANOTHER AREA OF
CONVECTION DEVELOPING UPSTREAM AHEAD OF A POTENT SHORT WAVE
TROUGH...WITH MORE DISCRETE CELLS WHICH MIGHT TRY TO ORGANIZE INTO
A QUASI-LINEAR CONVECTIVE SYSTEM /QLCS/ ALONG AN OUTFLOW OR WIND
SHIFT BOUNDARY STRETCHING ACROSS SOUTH-CENTRAL GEORGIA THROUGH
MID-EVENING.

THERE ARE MANY FACTORS WHICH WILL INFLUENCE THE POTENTIAL FOR
STRONG TO SEVERE THUNDERSTORMS TODAY. AS THE WEAKENING MCS MOVES
INTO THE AREA...TIMING WILL BE SOMEWHAT UNFAVORABLE AS THE
REMNANTS MOVE THROUGH JUST PAST THE TYPICAL DIURNAL MINIMUM. WHILE
SOME STRENGTHENING COULD OCCUR AS THE CONVECTION PROGRESSES ACROSS
THE AREA INTO EARLY AFTERNOON...EXTENSIVE CLOUD COVER WILL LIMIT
SURFACE-BASED INSTABILITY AND THE THREAT FOR SEVERE WEATHER
APPEARS MARGINAL. IF THE ATMOSPHERE DOES NOT BECOME TOO WORKED
OVER...IT APPEARS THAT SURFACE-BASED INSTABILITY COULD INCREASE
WITH CAPE VALUES REACHING UPWARDS OF 1500-1750 J/KG...ESPECIALLY
IF ANY BREAKS DEVELOP IN THE CLOUD COVER. THIS WOULD SUPPORT A
MORE FAVORABLE ENVIRONMENT FOR SEVERE THUNDERSTORMS. THE MOST
PROBABLE TIMING FOR SEVERE THUNDERSTORMS APPEARS TO BE FROM 4 PM
TO 9 PM...ALTHOUGH AS MENTIONED EARLIER SOME OF THE CONVECTION IN
THE EARLY AFTERNOON COULD BE STRONG IF NOT MARGINALLY SEVERE AS
WELL. STRENGTHENING LOW LEVEL WIND FIELDS WILL RESULT IN A THREAT
FOR DAMAGING WINDS...AND IMPRESSIVE DEEP LAYER SHEAR WITH 0-3KM
HELICITY VALUES UPWARDS OF 300-400 M2/S2 WOULD SUPPORT A SMALL
RISK FOR TORNADOES. IT SHOULD ALSO BE NOTED THAT THE SEVERE
HAZARDS IN ENVIRONMENTS WITH REDUCED BUOYANCY /SHERB/
PARAMETER...WHICH IS USEFUL IN HIGH SHEAR LOW CAPE /HSLC/
EVENTS...REACHES OVER THE CRITICAL VALUES OF 1.0 IN BOTH THE NAM12
AND GFS LATE THIS AFTERNOON ACROSS SOUTHEAST GEORGIA. THIS
SUGGESTS A GREATER POTENTIAL FOR SIGNIFICANT SEVERE WEATHER ACROSS
THIS AREA.

GIVEN THE AFOREMENTIONED FACTORS...IT IS VERY POSSIBLE THAT A
SEVERE THUNDERSTORM OR TORNADO WATCH COULD BE ISSUED FOR PARTS OF
THE AREA LATER THIS AFTERNOON INTO THIS EVENING. AGAIN...THE
GREATEST THREATS WILL BE DAMAGING WINDS...ISOLATED
TORNADOES...FREQUENT LIGHTNING AND LOCALLY HEAVY RAINFALL. THESE
WILL ALL CONTINUE TO BE ADDRESSED IN THE HAZARDOUS WEATHER
OUTLOOK.

LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND SUBSIDENCE
DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE DISTURBANCE. LOWS
SHOULD BE IN THE MID TO UPPER 6S ACROSS THE AREA.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL AT KCHS AND KSAV UNTIL CONDITIONS
BEGIN TO DETERIORATE AROUND MIDDAY AS SHOWERS AND THUNDERSTORMS
SPREAD ACROSS THE AREA AS A WARM FRONT LIFTS NORTH. EXPECT MVFR OR
LOWER CONDITIONS TO DEVELOP WITHIN THE SHOWERS AND
THUNDERSTORMS...ROUGHLY IN THE 16-23Z TIME FRAME. THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING STRONG/ERRATIC WINDS...HEAVY RAIN AND
FREQUENT LIGHTNING. EVEN OUTSIDE OF CONVECTION...WINDS WILL BE
BREEZY THIS AFTERNOON WITH GUSTS UPWARDS OF AROUND 20 KT. SOME
SHOWERS COULD LINGER INTO LATE THIS EVENING...BUT VFR CONDITIONS
ARE GENERALLY EXPECTED ONCE THE BULK OF THE CONVECTION MOVES
THROUGH. LINGERING LOW LEVEL MOISTURE COULD PRODUCE SOME MVFR OR
LOWER CEILINGS TOWARD DAYBREAK SUNDAY. LOW LEVEL WIND SHEAR COULD
BE A FACTOR AT BOTH TERMINALS AFTER 03Z AS WINDS INCREASE TO
35-40 KT WITHIN 2K FT OF THE SURFACE.

EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN MVFR CIGS SUNDAY
NIGHT WITH A COLD FRONTAL PASSAGE. BREEZY SUNDAY AFTERNOON WITH
GUSTS TO 25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL
INTO TUE BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

NEAR TERM...JAQ
SHORT TERM...RJB
LONG TERM...RJB
AVIATION...JAQ/RJB
MARINE...JAQ/RJB




000
FXUS62 KCHS 251145
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
745 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...A RATHER ILL-DEFINED WARM FRONT WILL LIFT NORTH OF THE
AREA THIS MORNING AS HIGH PRESSURE OVER THE WESTERN ATLANTIC
CONTINUES TO SHIFT FARTHER FROM THE COAST. TEMPERATURE RISES MAY
BE HELD BACK BY SIGNIFICANT CLOUD COVER TODAY...BUT WITH STRONG
WARM AIR ADVECTION TAKING PLACE STILL EXPECT TO SEE HIGHS RANGING
FROM THE MID AND UPPER 70S ACROSS SOUTHEAST SOUTH CAROLINA AND
LOWER 80S ACROSS SOUTHEAST GEORGIA. BREEZY CONDITIONS ARE ALSO
EXPECTED THIS AFTERNOON.

THE CHARACTER/TIMING OF CONVECTION IS VERY DIFFICULT TO PIN DOWN
TODAY GIVEN VARYING MODEL SOLUTIONS. INITIALLY...SOME
PATCHY LIGHT RAIN SHOWERS COULD OCCUR ACROSS PARTS OF SOUTHEAST
SOUTH CAROLINA THROUGH MID-MORNING ONCE THE LOWER LEVELS OF THE
ATMOSPHERE MOISTEN DUE TO ISENTROPIC ASCENT ASSOCIATED WITH THE
WARM FRONT. THIS AREA OF OVERRUNNING PRECIPITATION WILL LIFT
OUT WITH THE WARM FRONT...THEN THE REMNANTS OF A MESOSCALE
CONVECTIVE COMPLEX /MCS/ SHOULD MOVE INTO THE AREA LATE THIS
MORNING AND CONTINUE TOWARD THE COAST THROUGH EARLY THIS
AFTERNOON WITH RAINFALL PROBABILITIES REACHING 80-100 PERCENT.
HIGH RESOLUTION MESOSCALE MODELS THEN SHOW ANOTHER AREA OF
CONVECTION DEVELOPING UPSTREAM AHEAD OF A POTENT SHORT WAVE
TROUGH...WITH MORE DISCRETE CELLS WHICH MIGHT TRY TO ORGANIZE INTO
A QUASI-LINEAR CONVECTIVE SYSTEM /QLCS/ ALONG AN OUTFLOW OR WIND
SHIFT BOUNDARY STRETCHING ACROSS SOUTH-CENTRAL GEORGIA THROUGH
MID-EVENING.

THERE ARE MANY FACTORS WHICH WILL INFLUENCE THE POTENTIAL FOR
STRONG TO SEVERE THUNDERSTORMS TODAY. AS THE WEAKENING MCS MOVES
INTO THE AREA...TIMING WILL BE SOMEWHAT UNFAVORABLE AS THE
REMNANTS MOVE THROUGH JUST PAST THE TYPICAL DIURNAL MINIMUM. WHILE
SOME STRENGTHENING COULD OCCUR AS THE CONVECTION PROGRESSES ACROSS
THE AREA INTO EARLY AFTERNOON...EXTENSIVE CLOUD COVER WILL LIMIT
SURFACE-BASED INSTABILITY AND THE THREAT FOR SEVERE WEATHER
APPEARS MARGINAL. IF THE ATMOSPHERE DOES NOT BECOME TOO WORKED
OVER...IT APPEARS THAT SURFACE-BASED INSTABILITY COULD INCREASE
WITH CAPE VALUES REACHING UPWARDS OF 1500-1750 J/KG...ESPECIALLY
IF ANY BREAKS DEVELOP IN THE CLOUD COVER. THIS WOULD SUPPORT A
MORE FAVORABLE ENVIRONMENT FOR SEVERE THUNDERSTORMS. THE MOST
PROBABLE TIMING FOR SEVERE THUNDERSTORMS APPEARS TO BE FROM 4 PM
TO 9 PM...ALTHOUGH AS MENTIONED EARLIER SOME OF THE CONVECTION IN
THE EARLY AFTERNOON COULD BE STRONG IF NOT MARGINALLY SEVERE AS
WELL. STRENGTHENING LOW LEVEL WIND FIELDS WILL RESULT IN A THREAT
FOR DAMAGING WINDS...AND IMPRESSIVE DEEP LAYER SHEAR WITH 0-3KM
HELICITY VALUES UPWARDS OF 300-400 M2/S2 WOULD SUPPORT A SMALL
RISK FOR TORNADOES. IT SHOULD ALSO BE NOTED THAT THE SEVERE
HAZARDS IN ENVIRONMENTS WITH REDUCED BUOYANCY /SHERB/
PARAMETER...WHICH IS USEFUL IN HIGH SHEAR LOW CAPE /HSLC/
EVENTS...REACHES OVER THE CRITICAL VALUES OF 1.0 IN BOTH THE NAM12
AND GFS LATE THIS AFTERNOON ACROSS SOUTHEAST GEORGIA. THIS
SUGGESTS A GREATER POTENTIAL FOR SIGNIFICANT SEVERE WEATHER ACROSS
THIS AREA.

GIVEN THE AFOREMENTIONED FACTORS...IT IS VERY POSSIBLE THAT A
SEVERE THUNDERSTORM OR TORNADO WATCH COULD BE ISSUED FOR PARTS OF
THE AREA LATER THIS AFTERNOON INTO THIS EVENING. AGAIN...THE
GREATEST THREATS WILL BE DAMAGING WINDS...ISOLATED
TORNADOES...FREQUENT LIGHTNING AND LOCALLY HEAVY RAINFALL. THESE
WILL ALL CONTINUE TO BE ADDRESSED IN THE HAZARDOUS WEATHER
OUTLOOK.

LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND SUBSIDENCE
DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE DISTURBANCE. LOWS
SHOULD BE IN THE MID TO UPPER 6S ACROSS THE AREA.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL AT KCHS AND KSAV UNTIL CONDITIONS
BEGIN TO DETERIORATE AROUND MIDDAY AS SHOWERS AND THUNDERSTORMS
SPREAD ACROSS THE AREA AS A WARM FRONT LIFTS NORTH. EXPECT MVFR OR
LOWER CONDITIONS TO DEVELOP WITHIN THE SHOWERS AND
THUNDERSTORMS...ROUGHLY IN THE 16-23Z TIME FRAME. THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING STRONG/ERRATIC WINDS...HEAVY RAIN AND
FREQUENT LIGHTNING. EVEN OUTSIDE OF CONVECTION...WINDS WILL BE
BREEZY THIS AFTERNOON WITH GUSTS UPWARDS OF AROUND 20 KT. SOME
SHOWERS COULD LINGER INTO LATE THIS EVENING...BUT VFR CONDITIONS
ARE GENERALLY EXPECTED ONCE THE BULK OF THE CONVECTION MOVES
THROUGH. LINGERING LOW LEVEL MOISTURE COULD PRODUCE SOME MVFR OR
LOWER CEILINGS TOWARD DAYBREAK SUNDAY. LOW LEVEL WIND SHEAR COULD
BE A FACTOR AT BOTH TERMINALS AFTER 03Z AS WINDS INCREASE TO
35-40 KT WITHIN 2K FT OF THE SURFACE.

EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN MVFR CIGS SUNDAY
NIGHT WITH A COLD FRONTAL PASSAGE. BREEZY SUNDAY AFTERNOON WITH
GUSTS TO 25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL
INTO TUE BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

NEAR TERM...JAQ
SHORT TERM...RJB
LONG TERM...RJB
AVIATION...JAQ/RJB
MARINE...JAQ/RJB



000
FXUS62 KGSP 251056
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
656 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...LLVL MOISTURE WILL RAPIDLY INCREASE FROM THE SOUTHWEST
DURING THE MID TO LATE MORNING HOURS...RESULTING IN MVFR CEILINGS
AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO THE AFTERNOON
AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING. BASED ON THE
TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES WILL DEVELOP
DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL HIGHLIGHT THE
22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE EVENING...FORECAST
SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND MODEL CLOUDS ARE
EASILY WITHIN IFR. WINDS THROUGH THIS EVENING WILL REMAIN FROM THE
SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A WELL ORGANIZED
SFC LOW OVER KY/TN. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. HOWEVER...EMBEDDED
THUNDERSTORMS MAY PASS ACROSS THE REGION DURING THE EARLY DAYLIGHT
HOURS. THE DEEP MOISTURE AND FORCING WILL SPREAD SW TO NE...REACHING
KHKY AROUND THE SAME PERIOD AS KCLT. KHKY MAY DEVELOP WINDS FROM THE
EAST-NORTHEAST AROUND SUNRISE...PERSISTING THROUGH THE REST OF THE
TAF PERIOD. ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            11-17Z        17-23Z        23-05Z        05-06Z
KCLT       HIGH 100%     MED   62%     MED   76%     MED   70%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     MED   71%     HIGH  93%     HIGH 100%
KHKY       HIGH 100%     MED   69%     MED   69%     LOW   53%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED



000
FXUS62 KGSP 251056
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
656 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...LLVL MOISTURE WILL RAPIDLY INCREASE FROM THE SOUTHWEST
DURING THE MID TO LATE MORNING HOURS...RESULTING IN MVFR CEILINGS
AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO THE AFTERNOON
AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING. BASED ON THE
TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES WILL DEVELOP
DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL HIGHLIGHT THE
22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE EVENING...FORECAST
SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND MODEL CLOUDS ARE
EASILY WITHIN IFR. WINDS THROUGH THIS EVENING WILL REMAIN FROM THE
SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A WELL ORGANIZED
SFC LOW OVER KY/TN. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. HOWEVER...EMBEDDED
THUNDERSTORMS MAY PASS ACROSS THE REGION DURING THE EARLY DAYLIGHT
HOURS. THE DEEP MOISTURE AND FORCING WILL SPREAD SW TO NE...REACHING
KHKY AROUND THE SAME PERIOD AS KCLT. KHKY MAY DEVELOP WINDS FROM THE
EAST-NORTHEAST AROUND SUNRISE...PERSISTING THROUGH THE REST OF THE
TAF PERIOD. ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            11-17Z        17-23Z        23-05Z        05-06Z
KCLT       HIGH 100%     MED   62%     MED   76%     MED   70%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     MED   71%     HIGH  93%     HIGH 100%
KHKY       HIGH 100%     MED   69%     MED   69%     LOW   53%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED



000
FXUS62 KGSP 251056
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
656 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...LLVL MOISTURE WILL RAPIDLY INCREASE FROM THE SOUTHWEST
DURING THE MID TO LATE MORNING HOURS...RESULTING IN MVFR CEILINGS
AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO THE AFTERNOON
AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING. BASED ON THE
TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES WILL DEVELOP
DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL HIGHLIGHT THE
22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE EVENING...FORECAST
SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND MODEL CLOUDS ARE
EASILY WITHIN IFR. WINDS THROUGH THIS EVENING WILL REMAIN FROM THE
SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A WELL ORGANIZED
SFC LOW OVER KY/TN. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. HOWEVER...EMBEDDED
THUNDERSTORMS MAY PASS ACROSS THE REGION DURING THE EARLY DAYLIGHT
HOURS. THE DEEP MOISTURE AND FORCING WILL SPREAD SW TO NE...REACHING
KHKY AROUND THE SAME PERIOD AS KCLT. KHKY MAY DEVELOP WINDS FROM THE
EAST-NORTHEAST AROUND SUNRISE...PERSISTING THROUGH THE REST OF THE
TAF PERIOD. ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            11-17Z        17-23Z        23-05Z        05-06Z
KCLT       HIGH 100%     MED   62%     MED   76%     MED   70%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     MED   71%     HIGH  93%     HIGH 100%
KHKY       HIGH 100%     MED   69%     MED   69%     LOW   53%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED



000
FXUS62 KGSP 251056
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
656 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 650 AM...I WILL ISSUE A QUICK UPDATE TO ADJUST POPS AND
TEMPERATURES TO OBSERVATIONS. OVERALL...THE CURRENT FORECAST APPEARS
ON TRACK.

AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...LLVL MOISTURE WILL RAPIDLY INCREASE FROM THE SOUTHWEST
DURING THE MID TO LATE MORNING HOURS...RESULTING IN MVFR CEILINGS
AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO THE AFTERNOON
AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING. BASED ON THE
TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES WILL DEVELOP
DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL HIGHLIGHT THE
22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE EVENING...FORECAST
SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND MODEL CLOUDS ARE
EASILY WITHIN IFR. WINDS THROUGH THIS EVENING WILL REMAIN FROM THE
SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A WELL ORGANIZED
SFC LOW OVER KY/TN. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. HOWEVER...EMBEDDED
THUNDERSTORMS MAY PASS ACROSS THE REGION DURING THE EARLY DAYLIGHT
HOURS. THE DEEP MOISTURE AND FORCING WILL SPREAD SW TO NE...REACHING
KHKY AROUND THE SAME PERIOD AS KCLT. KHKY MAY DEVELOP WINDS FROM THE
EAST-NORTHEAST AROUND SUNRISE...PERSISTING THROUGH THE REST OF THE
TAF PERIOD. ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30. AS THE LOW PUSHES ACROSS THE PIEDMONT LATE
TONIGHT...WINDS WILL SHIFT FROM THE NE AND CLOUD BASES WILL RISE TO
VFR. IN ADDITION...IN THE WAKE OF THE LOW...LLVL WINDS SHOULD
STRENGTHEN...RESULTING IN LLWS FROM 5Z THROUGH 12Z.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            11-17Z        17-23Z        23-05Z        05-06Z
KCLT       HIGH 100%     MED   62%     MED   76%     MED   70%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     MED   71%     HIGH  93%     HIGH 100%
KHKY       HIGH 100%     MED   69%     MED   69%     LOW   53%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED



000
FXUS62 KCHS 250939
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
539 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...A RATHER ILL-DEFINED WARM FRONT WILL LIFT NORTH OF THE
AREA THIS MORNING AS HIGH PRESSURE OVER THE WESTERN ATLANTIC
CONTINUES TO SHIFT FARTHER FROM THE COAST. TEMPERATURE RISES MAY
BE HELD BACK BY SIGNIFICANT CLOUD COVER TODAY...BUT WITH STRONG
WARM AIR ADVECTION TAKING PLACE STILL EXPECT TO SEE HIGHS RANGING
FROM THE MID AND UPPER 70S ACROSS SOUTHEAST SOUTH CAROLINA AND
LOWER 80S ACROSS SOUTHEAST GEORGIA. BREEZY CONDITIONS ARE ALSO
EXPECTED THIS AFTERNOON.

THE CHARACTER/TIMING OF CONVECTION IS VERY DIFFICULT TO PIN DOWN
TODAY GIVEN VARYING MODEL SOLUTIONS. INITIALLY...SOME
PATCHY LIGHT RAIN SHOWERS COULD OCCUR ACROSS PARTS OF SOUTHEAST
SOUTH CAROLINA THROUGH MID-MORNING ONCE THE LOWER LEVELS OF THE
ATMOSPHERE MOISTEN DUE TO ISENTROPIC ASCENT ASSOCIATED WITH THE
WARM FRONT. THIS AREA OF OVERRUNNING PRECIPITATION WILL LIFT
OUT WITH THE WARM FRONT...THEN THE REMNANTS OF A MESOSCALE
CONVECTIVE COMPLEX /MCS/ SHOULD MOVE INTO THE AREA LATE THIS
MORNING AND CONTINUE TOWARD THE COAST THROUGH EARLY THIS
AFTERNOON WITH RAINFALL PROBABILITIES REACHING 80-100 PERCENT.
HIGH RESOLUTION MESOSCALE MODELS THEN SHOW ANOTHER AREA OF
CONVECTION DEVELOPING UPSTREAM AHEAD OF A POTENT SHORT WAVE
TROUGH...WITH MORE DISCRETE CELLS WHICH MIGHT TRY TO ORGANIZE INTO
A QUASI-LINEAR CONVECTIVE SYSTEM /QLCS/ ALONG AN OUTFLOW OR WIND
SHIFT BOUNDARY STRETCHING ACROSS SOUTH-CENTRAL GEORGIA THROUGH
MID-EVENING.

THERE ARE MANY FACTORS WHICH WILL INFLUENCE THE POTENTIAL FOR
STRONG TO SEVERE THUNDERSTORMS TODAY. AS THE WEAKENING MCS MOVES
INTO THE AREA...TIMING WILL BE SOMEWHAT UNFAVORABLE AS THE
REMNANTS MOVE THROUGH JUST PAST THE TYPICAL DIURNAL MINIMUM. WHILE
SOME STRENGTHENING COULD OCCUR AS THE CONVECTION PROGRESSES ACROSS
THE AREA INTO EARLY AFTERNOON...EXTENSIVE CLOUD COVER WILL LIMIT
SURFACE-BASED INSTABILITY AND THE THREAT FOR SEVERE WEATHER
APPEARS MARGINAL. IF THE ATMOSPHERE DOES NOT BECOME TOO WORKED
OVER...IT APPEARS THAT SURFACE-BASED INSTABILITY COULD INCREASE
WITH CAPE VALUES REACHING UPWARDS OF 1500-1750 J/KG...ESPECIALLY
IF ANY BREAKS DEVELOP IN THE CLOUD COVER. THIS WOULD SUPPORT A
MORE FAVORABLE ENVIRONMENT FOR SEVERE THUNDERSTORMS. THE MOST
PROBABLE TIMING FOR SEVERE THUNDERSTORMS APPEARS TO BE FROM 4 PM
TO 9 PM...ALTHOUGH AS MENTIONED EARLIER SOME OF THE CONVECTION IN
THE EARLY AFTERNOON COULD BE STRONG IF NOT MARGINALLY SEVERE AS
WELL. STRENGTHENING LOW LEVEL WIND FIELDS WILL RESULT IN A THREAT
FOR DAMAGING WINDS...AND IMPRESSIVE DEEP LAYER SHEAR WITH 0-3KM
HELICITY VALUES UPWARDS OF 300-400 M2/S2 WOULD SUPPORT A SMALL
RISK FOR TORNADOES. IT SHOULD ALSO BE NOTED THAT THE SEVERE
HAZARDS IN ENVIRONMENTS WITH REDUCED BUOYANCY /SHERB/
PARAMETER...WHICH IS USEFUL IN HIGH SHEAR LOW CAPE /HSLC/
EVENTS...REACHES OVER THE CRITICAL VALUES OF 1.0 IN BOTH THE NAM12
AND GFS LATE THIS AFTERNOON ACROSS SOUTHEAST GEORGIA. THIS
SUGGESTS A GREATER POTENTIAL FOR SIGNIFICANT SEVERE WEATHER ACROSS
THIS AREA.

GIVEN THE AFOREMENTIONED FACTORS...IT IS VERY POSSIBLE THAT A
SEVERE THUNDERSTORM OR TORNADO WATCH COULD BE ISSUED FOR PARTS OF
THE AREA LATER THIS AFTERNOON INTO THIS EVENING. AGAIN...THE
GREATEST THREATS WILL BE DAMAGING WINDS...ISOLATED
TORNADOES...FREQUENT LIGHTNING AND LOCALLY HEAVY RAINFALL. THESE
WILL ALL CONTINUE TO BE ADDRESSED IN THE HAZARDOUS WEATHER
OUTLOOK.

LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND SUBSIDENCE
DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE DISTURBANCE. LOWS
SHOULD BE IN THE MID TO UPPER 6S ACROSS THE AREA.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL AT KCHS AND KSAV UNTIL CONDITIONS
BEGIN TO DETERIORATE AROUND MIDDAY AS SHOWERS AND THUNDERSTORMS
SPREAD ACROSS THE AREA AS A WARM FRONT LIFTS NORTH. EXPECT MVFR OR
LOWER CONDITIONS TO DEVELOP WITHIN THE SHOWERS AND
THUNDERSTORMS...ROUGHLY IN THE 17-22Z TIME FRAME. THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING STRONG/ERRATIC WINDS...HEAVY RAIN AND
FREQUENT LIGHTNING. EVEN OUTSIDE OF CONVECTION...WINDS WILL BE
BREEZY THIS AFTERNOON WITH GUSTS UPWARDS OF AROUND 20 KT. SOME
SHOWERS COULD LINGER INTO EARLY THIS EVENING...BUT VFR CONDITIONS
ARE GENERALLY EXPECTED ONCE THE BULK OF THE CONVECTION MOVES
THROUGH. LOW LEVEL WIND SHEAR COULD BECOME AN ISSUE LATE
TONIGHT...BUT GENERALLY AFTER 06Z.

EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN MVFR CIGS SUNDAY
NIGHT WITH A COLD FRONTAL PASSAGE. BREEZY SUNDAY AFTERNOON WITH
GUSTS TO 25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL
INTO TUE BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

NEAR TERM...JAQ
SHORT TERM...RJB
LONG TERM...RJB
AVIATION...JAQ/RJB
MARINE...JAQ/RJB



000
FXUS62 KCHS 250939
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
539 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH OF THE AREA THIS MORNING...FOLLOWED
BY THE PASSAGE OF A DISTURBANCE FROM THE WEST THIS AFTERNOON AND
EVENING. A COLD FRONT WILL THEN MOVE SOUTH THROUGH THE AREA
SUNDAY NIGHT. DRY HIGH PRESSURE WILL PREVAIL MONDAY INTO TUESDAY.
A GULF OF MEXICO STORM SYSTEM WILL IMPACT THE REGION MID WEEK WITH
DRY HIGH PRESSURE THEN LIKELY RETURNING THROUGH THE END OF THE
WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...A RATHER ILL-DEFINED WARM FRONT WILL LIFT NORTH OF THE
AREA THIS MORNING AS HIGH PRESSURE OVER THE WESTERN ATLANTIC
CONTINUES TO SHIFT FARTHER FROM THE COAST. TEMPERATURE RISES MAY
BE HELD BACK BY SIGNIFICANT CLOUD COVER TODAY...BUT WITH STRONG
WARM AIR ADVECTION TAKING PLACE STILL EXPECT TO SEE HIGHS RANGING
FROM THE MID AND UPPER 70S ACROSS SOUTHEAST SOUTH CAROLINA AND
LOWER 80S ACROSS SOUTHEAST GEORGIA. BREEZY CONDITIONS ARE ALSO
EXPECTED THIS AFTERNOON.

THE CHARACTER/TIMING OF CONVECTION IS VERY DIFFICULT TO PIN DOWN
TODAY GIVEN VARYING MODEL SOLUTIONS. INITIALLY...SOME
PATCHY LIGHT RAIN SHOWERS COULD OCCUR ACROSS PARTS OF SOUTHEAST
SOUTH CAROLINA THROUGH MID-MORNING ONCE THE LOWER LEVELS OF THE
ATMOSPHERE MOISTEN DUE TO ISENTROPIC ASCENT ASSOCIATED WITH THE
WARM FRONT. THIS AREA OF OVERRUNNING PRECIPITATION WILL LIFT
OUT WITH THE WARM FRONT...THEN THE REMNANTS OF A MESOSCALE
CONVECTIVE COMPLEX /MCS/ SHOULD MOVE INTO THE AREA LATE THIS
MORNING AND CONTINUE TOWARD THE COAST THROUGH EARLY THIS
AFTERNOON WITH RAINFALL PROBABILITIES REACHING 80-100 PERCENT.
HIGH RESOLUTION MESOSCALE MODELS THEN SHOW ANOTHER AREA OF
CONVECTION DEVELOPING UPSTREAM AHEAD OF A POTENT SHORT WAVE
TROUGH...WITH MORE DISCRETE CELLS WHICH MIGHT TRY TO ORGANIZE INTO
A QUASI-LINEAR CONVECTIVE SYSTEM /QLCS/ ALONG AN OUTFLOW OR WIND
SHIFT BOUNDARY STRETCHING ACROSS SOUTH-CENTRAL GEORGIA THROUGH
MID-EVENING.

THERE ARE MANY FACTORS WHICH WILL INFLUENCE THE POTENTIAL FOR
STRONG TO SEVERE THUNDERSTORMS TODAY. AS THE WEAKENING MCS MOVES
INTO THE AREA...TIMING WILL BE SOMEWHAT UNFAVORABLE AS THE
REMNANTS MOVE THROUGH JUST PAST THE TYPICAL DIURNAL MINIMUM. WHILE
SOME STRENGTHENING COULD OCCUR AS THE CONVECTION PROGRESSES ACROSS
THE AREA INTO EARLY AFTERNOON...EXTENSIVE CLOUD COVER WILL LIMIT
SURFACE-BASED INSTABILITY AND THE THREAT FOR SEVERE WEATHER
APPEARS MARGINAL. IF THE ATMOSPHERE DOES NOT BECOME TOO WORKED
OVER...IT APPEARS THAT SURFACE-BASED INSTABILITY COULD INCREASE
WITH CAPE VALUES REACHING UPWARDS OF 1500-1750 J/KG...ESPECIALLY
IF ANY BREAKS DEVELOP IN THE CLOUD COVER. THIS WOULD SUPPORT A
MORE FAVORABLE ENVIRONMENT FOR SEVERE THUNDERSTORMS. THE MOST
PROBABLE TIMING FOR SEVERE THUNDERSTORMS APPEARS TO BE FROM 4 PM
TO 9 PM...ALTHOUGH AS MENTIONED EARLIER SOME OF THE CONVECTION IN
THE EARLY AFTERNOON COULD BE STRONG IF NOT MARGINALLY SEVERE AS
WELL. STRENGTHENING LOW LEVEL WIND FIELDS WILL RESULT IN A THREAT
FOR DAMAGING WINDS...AND IMPRESSIVE DEEP LAYER SHEAR WITH 0-3KM
HELICITY VALUES UPWARDS OF 300-400 M2/S2 WOULD SUPPORT A SMALL
RISK FOR TORNADOES. IT SHOULD ALSO BE NOTED THAT THE SEVERE
HAZARDS IN ENVIRONMENTS WITH REDUCED BUOYANCY /SHERB/
PARAMETER...WHICH IS USEFUL IN HIGH SHEAR LOW CAPE /HSLC/
EVENTS...REACHES OVER THE CRITICAL VALUES OF 1.0 IN BOTH THE NAM12
AND GFS LATE THIS AFTERNOON ACROSS SOUTHEAST GEORGIA. THIS
SUGGESTS A GREATER POTENTIAL FOR SIGNIFICANT SEVERE WEATHER ACROSS
THIS AREA.

GIVEN THE AFOREMENTIONED FACTORS...IT IS VERY POSSIBLE THAT A
SEVERE THUNDERSTORM OR TORNADO WATCH COULD BE ISSUED FOR PARTS OF
THE AREA LATER THIS AFTERNOON INTO THIS EVENING. AGAIN...THE
GREATEST THREATS WILL BE DAMAGING WINDS...ISOLATED
TORNADOES...FREQUENT LIGHTNING AND LOCALLY HEAVY RAINFALL. THESE
WILL ALL CONTINUE TO BE ADDRESSED IN THE HAZARDOUS WEATHER
OUTLOOK.

LATE THIS EVENING AND OVERNIGHT...SOME LINGERING CONVECTION WILL
PERSIST INTO THE LATE EVENING...ALTHOUGH THE POTENTIAL FOR ANY
SEVERE THUNDERSTORMS SHOULD BE GREATLY REDUCED BY THIS TIME. THE
BULK OF THE OVERNIGHT SHOULD BE RAIN-FREE AS THE COLUMN DRIES AND SUBSIDENCE
DEVELOPS IN WAKE OF THE DEPARTING SHORT WAVE DISTURBANCE. LOWS
SHOULD BE IN THE MID TO UPPER 6S ACROSS THE AREA.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY...GENERALLY DRY WITH TEMPS NEAR 90 GIVEN STRONG OFFSHORE
WINDS AND MAINLY SUNNY SKIES. MOISTURE WILL INCREASE THOUGH SUNDAY
NIGHT AS A BACKDOOR COLD FRONT SOUTHWARD THROUGH THE AREA AND A FEW
SHOWERS AND THUNDERSTORMS ARE POSSIBLE AS A RESULT.

MONDAY...HIGH PRESSURE WILL PREVAIL WITH DRY WEATHER AND
TEMPERATURES DIPPING BELOW NORMAL INTO THE LOWER TO MID 70S.

TUESDAY...HIGH PRESSURE WILL CONTINUE FROM THE NORTH AS LOW PRESSURE
BEGINS TO DEVELOP OVER THE NORTHERN GULF OF MEXICO. COULD SEE SOME
LATE SHOWERS NEAR THE ALTAMAHA BUT MOST AREAS SHOULD REMAIN DRY.
TEMPERATURES WILL BE COOLER THAN MONDAY...PROBABLY MORE LIKE THE
LOWER 70S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
RAIN CHANCES WILL BE INCREASING FROM THE SOUTHWEST TUESDAY NIGHT AS
DEVELOPING LOW PRESSURE ALONG THE NORTHERN GULF COAST MOVES TOWARD
THE AREA ALONG WITH DEEPER MOISTURE. STILL SOME TIMING/STRENGTH
DIFFERENCES THOUGH WITH THIS SYSTEM WITH THE ECMWF CONTINUING TO BE
FASTER AND STRONGER WITH THE LOW AS IT MOVES THROUGH SOUTHEAST
GEORGIA WEDNESDAY/WEDNESDAY NIGHT. THE LOW SHOULD BE PULLING AWAY
FROM THE AREA THURSDAY WITH IMPROVING CONDITIONS...ALTHOUGH CANNOT
RULE OUT SOME LINGERING SHOWERS AS DUE TO THE SLOW PROGRESSION OF
THE UPPER TROUGH. FRIDAY AND SATURDAY LOOK DRIER WITH TEMPS GETTING
BACK TO AT OR JUST ABOVE NORMAL.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL PREVAIL AT KCHS AND KSAV UNTIL CONDITIONS
BEGIN TO DETERIORATE AROUND MIDDAY AS SHOWERS AND THUNDERSTORMS
SPREAD ACROSS THE AREA AS A WARM FRONT LIFTS NORTH. EXPECT MVFR OR
LOWER CONDITIONS TO DEVELOP WITHIN THE SHOWERS AND
THUNDERSTORMS...ROUGHLY IN THE 17-22Z TIME FRAME. THUNDERSTORMS
WILL BE CAPABLE OF PRODUCING STRONG/ERRATIC WINDS...HEAVY RAIN AND
FREQUENT LIGHTNING. EVEN OUTSIDE OF CONVECTION...WINDS WILL BE
BREEZY THIS AFTERNOON WITH GUSTS UPWARDS OF AROUND 20 KT. SOME
SHOWERS COULD LINGER INTO EARLY THIS EVENING...BUT VFR CONDITIONS
ARE GENERALLY EXPECTED ONCE THE BULK OF THE CONVECTION MOVES
THROUGH. LOW LEVEL WIND SHEAR COULD BECOME AN ISSUE LATE
TONIGHT...BUT GENERALLY AFTER 06Z.

EXTENDED AVIATION OUTLOOK...HIGH CONFIDENCE IN MVFR CIGS SUNDAY
NIGHT WITH A COLD FRONTAL PASSAGE. BREEZY SUNDAY AFTERNOON WITH
GUSTS TO 25 TO POSSIBLY 30 KT. VFR CONDITIONS SHOULD THEN PREVAIL
INTO TUE BEFORE SHOWERS AND TSTMS RETURN MAINLY TUESDAY NIGHT INTO
WEDNESDAY NIGHT.

&&

.MARINE...
TODAY AND TONIGHT...SOUTHERLY WINDS WILL STRENGTHEN TODAY INTO
TONIGHT AS A WARM FRONT LIFTS NORTH OF THE AREA AND STRONG LOW
LEVEL WIND FIELDS SPREAD OVER THE AREA. WIND SPEEDS SHOULD PEAK
AROUND 15-20 KT BY LATE THIS AFTERNOON...THEN INCREASE FURTHER
INTO THE 20-25 KT RANGE OVERNIGHT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL ALSO STEADILY BUILD...PEAKING 3-5 FT NEARSHORE WATERS AND 4-6 FT
OFFSHORE WATERS JUST AFTER MIDNIGHT AND EARLY SUNDAY MORNING. A
SMALL CRAFT ADVISORY HAS THEREFORE BEEN ISSUED FOR THE OUTER
GEORGIA WATERS BEGINNING AT 11 PM THIS EVENING. A SMALL CRAFT
ADVISORY MAY BE NEEDED FOR THE OUTER PORTION OF THE CHARLESTON
COUNTY COASTAL WATERS AS WELL WITH LATER FORECASTS.

SUNDAY THROUGH THURSDAY...WINDS WILL REMAIN ELEVATED FROM THE WEST
SUNDAY AHEAD OF A BACKDOOR COLD FRONT WHICH SHOULD PUSH SOUTH
THROUGH THE WATERS SUNDAY NIGHT. A NORTHERLY SURGE WILL ENSUE WITH
CONDITIONS NEAR ADVISORY LEVELS MAINLY BEYOND 20 NM. HIGH PRESSURE
BUILDING FROM THE NORTH SHOULD LEAD TO A WEAKENING PRESSURE GRADIENT
AND THUS WINDS AS WELL INTO MONDAY NIGHT BEFORE CONDITIONS GO BACK
DOWNHILL AS DEVELOPING LOW PRESSURE APPROACHES FROM THE SOUTHWEST
WEDNESDAY AND PASSES THROUGH THE AREA WEDNESDAY NIGHT...WITH SMALL
CRAFT ADVISORIES POSSIBLY BEING NEEDED FOR AT LEAST THE WATERS
BEYOND 20 NM FROM SHORE. THERE IS STILL SOME UNCERTAINTY THOUGH
REGARDING THE STRENGTH/TRACK/TIMING OF THE LOW AND THUS FORECAST
CONFIDENCE IS LOW AT THIS TIME.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
     SUNDAY FOR AMZ374.

&&

$$

NEAR TERM...JAQ
SHORT TERM...RJB
LONG TERM...RJB
AVIATION...JAQ/RJB
MARINE...JAQ/RJB




000
FXUS62 KGSP 250927
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
527 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE NC
PIEDMONT THROUGH SUNRISE. LLVL MOISTURE SHOULD RAPIDLY INCREASE FROM
THE SOUTHWEST DURING THE MID TO LATE MORNING HOURS...RESULTING IN
MVFR CEILINGS AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO
THE AFTERNOON AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING.
BASED ON THE TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES
WILL DEVELOP DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL
HIGHLIGHT THE 22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE
EVENING...FORECAST SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND
MODEL CLOUDS ARE EASILY WITHIN IFR. WINDS DURING THE 6Z TAF WILL
REMAIN FROM THE SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A
WELL ORGANIZED SFC LOW OVER KY/TN.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. THE DEEP MOISTURE AND
FORCING WILL SPREAD SW TO NE...REACHING KHKY AROUND THE SAME PERIOD
AS KCLT. KHKY MAY DEVELOP WINDS FROM THE EAST-NORTHEAST AROUND
SUNRISE...PERSISTING THROUGH THE REST OF THE TAF PERIOD.
ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            09-15Z        15-21Z        21-03Z        03-06Z
KCLT       HIGH 100%     MED   66%     HIGH  91%     HIGH  80%
KGSP       HIGH 100%     MED   62%     HIGH  88%     HIGH  89%
KAVL       HIGH 100%     MED   64%     MED   76%     HIGH 100%
KHKY       HIGH 100%     MED   73%     HIGH  91%     MED   75%
KGMU       HIGH 100%     MED   71%     MED   79%     HIGH  89%
KAND       HIGH 100%     MED   68%     HIGH  97%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED




000
FXUS62 KGSP 250927
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
527 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 525 AM...WIDESPREAD CONVECTION ACROSS THE NORTHERN HALF OF AL
WILL CONTINUE TO TRACK EAST THIS MORNING. A LARGE AREA OF -RA WILL
GRADUALLY INCREASE ACROSS THE WESTERN CAROLINAS AHEAD OF THE DEEP
CONVECTION. I WILL UPDATE THE FORECAST TO MAKE MINOR TWEAKS TO THE
POP TRENDS. IN ADDITION...I WILL UPDATE TEMPERATURES TO INDICATE
VALUES NEARLY STEADY THROUGH SUNRISE.

AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE NC
PIEDMONT THROUGH SUNRISE. LLVL MOISTURE SHOULD RAPIDLY INCREASE FROM
THE SOUTHWEST DURING THE MID TO LATE MORNING HOURS...RESULTING IN
MVFR CEILINGS AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO
THE AFTERNOON AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING.
BASED ON THE TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES
WILL DEVELOP DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL
HIGHLIGHT THE 22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE
EVENING...FORECAST SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND
MODEL CLOUDS ARE EASILY WITHIN IFR. WINDS DURING THE 6Z TAF WILL
REMAIN FROM THE SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A
WELL ORGANIZED SFC LOW OVER KY/TN.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. THE DEEP MOISTURE AND
FORCING WILL SPREAD SW TO NE...REACHING KHKY AROUND THE SAME PERIOD
AS KCLT. KHKY MAY DEVELOP WINDS FROM THE EAST-NORTHEAST AROUND
SUNRISE...PERSISTING THROUGH THE REST OF THE TAF PERIOD.
ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            09-15Z        15-21Z        21-03Z        03-06Z
KCLT       HIGH 100%     MED   66%     HIGH  91%     HIGH  80%
KGSP       HIGH 100%     MED   62%     HIGH  88%     HIGH  89%
KAVL       HIGH 100%     MED   64%     MED   76%     HIGH 100%
KHKY       HIGH 100%     MED   73%     HIGH  91%     MED   75%
KGMU       HIGH 100%     MED   71%     MED   79%     HIGH  89%
KAND       HIGH 100%     MED   68%     HIGH  97%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED



000
FXUS62 KCAE 250829
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
429 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT LIFTING NORTHWARD INTO THE AREA TODAY WILL BE THE FOCUS
FOR SHOWERS AND SOME THUNDERSTORMS TODAY. DRIER WEATHER RETURNS FOR
SUNDAY AS A COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /THROUGH TONIGHT/...
A WARM FRONT WILL LIFT NORTHWARD INTO THE AREA TODAY. PRECIPITABLE
WATER VALUES RAPIDLY INCREASE TO OVER ONE INCH BY SUNRISE...AND
NEAR 1.80 INCHES FOR THIS AFTERNOON. ISENTROPIC LIFT AND WARM
ADVECTION THIS MORNING WILL BRING WIDESPREAD SHOWERS TO THE AREA.
CATEGORICAL POPS LOOK IN ORDER FOR THIS MORNING. AS THE WARM FRONT
LIFTS NORTH THE AIRMASS WILL DESTABILIZE WITH INCREASING SPEED AND
DIRECTIONAL SHEAR...WHICH SUPPORT ROTATION STORMS. INSTABILITY
WILL BE LIMITED UNTIL LATE AFTERNOON AND TONIGHT WHEN LI VALUES
REACH MINUS 4C TO MINUS 5C AND CAPE AROUND 1500 J/KG.

POTENTIAL FOR SEVERE STORMS WITH TWO WAVES POSSIBLE. THE FIRST
IS ASSOCIATED WITH AN MCS COMPLEX PUSHING EASTWARD TO ARRIVE
AROUND MIDDAY INTO EARLY AFTERNOON...WITH FAVORABLE JET STREAM
DYNAMICS. ANOTHER ROUND EXPECTED TO ARRIVE THIS EVENING WHEN DRIER
AIR ALOFT REACHES THE AREA...COMBINED WITH THE BEST INSTABILITY.
SPC HAS OUR ENTIRE AREA IN A SLIGHT RISK WITH AN AREA OF ENHANCED
RISK ACROSS TN/KY.

TEMPERATURES TODAY WILL BE LIMITED BY THE CLOUDS AND RAINFALL FOR
MUCH OF THE DAY BUT THERE IS SOME UNCERTAINTY ABOUT SOME POSSIBLE
RECOVERY LATE. WE SHOULD SEE A GRADIENT IN TEMPS FROM THE 60S
NORTH TO 70S SOUTH.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS NOTED ON SUNDAY
BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO WILL
CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.


&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
MEDIUM RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. LATEST GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE
WEST FRIDAY. TEMPERATURES GENERALLY AT OR JUST BELOW NORMAL
THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH AROUND 12Z THEN LOWER
CONFIDENCE AS MVFR RESTRICTIONS EXPECTED TO DEVELOP ALL TERMINALS
AS WIDESPREAD RAIN OVERSPREADS THE REGION ASSOCIATED WITH WARM
ADVECTION AS A WARM FRONT LIFTS NORTHWARD. LIGHT RAIN EXPECTED TO
IMPACT THE TERMINALS AFTER 12Z WITH MVFR CIGS/VSBYS SETTING IN
BETWEEN 14Z-16Z. LIGHT SOUTH TO SOUTHEASTERLY WINDS SHOULD
DEVELOP BY 12Z AND GRADUALLY SHIFT TO THE SOUTH AND EVENTUALLY
SOUTHWEST AS A WARM FRONT LIFTS NORTH THROUGH THE REGION THOUGH
THE DAY. SOME CONVECTION WITH STRONG THUNDERSTORMS POSSIBLE AFTER
16Z THROUGH 03Z-06Z TONIGHT BUT TIMING AND LOCATION STILL
UNCERTAIN SO WILL ONLY MENTION RAIN FOR NOW. CIGS SHOULD BECOME
MORE BROKEN OR SCATTERED LATE AFTERNOON AS THE WARM FRONT LIFTS
NORTHWARD BUT TIMING REMAINS UNCERTAIN.

LOW-LEVEL WIND SHEAR MAY BE AN ISSUE BEFORE WARM FRONTAL PASSAGE.
HIGH SHEAR AND INSTABILITY NEAR THE WARM FRONT MAY HELP SUPPORT
SEVERE THUNDERSTORMS WITH DAMAGING WIND AND HAIL SATURDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...SHOWERS AND THUNDERSTORMS WITH
ASSOCIATED RESTRICTIONS WILL BE POSSIBLE INTO SATURDAY EVENING.
BREEZY CONDITIONS POSSIBLE SUNDAY. NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCAE 250829
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
429 AM EDT SAT APR 25 2015

.SYNOPSIS...
A WARM FRONT LIFTING NORTHWARD INTO THE AREA TODAY WILL BE THE FOCUS
FOR SHOWERS AND SOME THUNDERSTORMS TODAY. DRIER WEATHER RETURNS FOR
SUNDAY AS A COLD FRONT MOVES ACROSS THE REGION. THE NEXT CHANCE FOR
SIGNIFICANT RAIN MOVES IN FOR THE MIDDLE OF NEXT WEEK AS MOISTURE
INCREASES AHEAD OF A LOW PRESSURE SYSTEM COMING OUT OF THE GULF OF
MEXICO.

&&

.NEAR TERM /THROUGH TONIGHT/...
A WARM FRONT WILL LIFT NORTHWARD INTO THE AREA TODAY. PRECIPITABLE
WATER VALUES RAPIDLY INCREASE TO OVER ONE INCH BY SUNRISE...AND
NEAR 1.80 INCHES FOR THIS AFTERNOON. ISENTROPIC LIFT AND WARM
ADVECTION THIS MORNING WILL BRING WIDESPREAD SHOWERS TO THE AREA.
CATEGORICAL POPS LOOK IN ORDER FOR THIS MORNING. AS THE WARM FRONT
LIFTS NORTH THE AIRMASS WILL DESTABILIZE WITH INCREASING SPEED AND
DIRECTIONAL SHEAR...WHICH SUPPORT ROTATION STORMS. INSTABILITY
WILL BE LIMITED UNTIL LATE AFTERNOON AND TONIGHT WHEN LI VALUES
REACH MINUS 4C TO MINUS 5C AND CAPE AROUND 1500 J/KG.

POTENTIAL FOR SEVERE STORMS WITH TWO WAVES POSSIBLE. THE FIRST
IS ASSOCIATED WITH AN MCS COMPLEX PUSHING EASTWARD TO ARRIVE
AROUND MIDDAY INTO EARLY AFTERNOON...WITH FAVORABLE JET STREAM
DYNAMICS. ANOTHER ROUND EXPECTED TO ARRIVE THIS EVENING WHEN DRIER
AIR ALOFT REACHES THE AREA...COMBINED WITH THE BEST INSTABILITY.
SPC HAS OUR ENTIRE AREA IN A SLIGHT RISK WITH AN AREA OF ENHANCED
RISK ACROSS TN/KY.

TEMPERATURES TODAY WILL BE LIMITED BY THE CLOUDS AND RAINFALL FOR
MUCH OF THE DAY BUT THERE IS SOME UNCERTAINTY ABOUT SOME POSSIBLE
RECOVERY LATE. WE SHOULD SEE A GRADIENT IN TEMPS FROM THE 60S
NORTH TO 70S SOUTH.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
SOME LINGERING SHOWERS/STORMS POSSIBLE INTO SUNDAY WITH THE NORTHERN
MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS THE SURFACE LOW
SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY SUNDAY EVENING.
MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS NOTED ON SUNDAY
BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH CONVECTION SO WILL
CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN MIDLANDS.

SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND DOWNSLOPING
NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S. THE EXCEPTION
WILL BE THE EXTREME NORTHERN MIDLANDS WHERE COOLER BEHIND THE AREA
OF LOW PRESSURE SHOULD HOLD TEMPERATURES IN THE 70S.


&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
MEDIUM RANGE MODELS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL
PATTERN NEXT WEEK. ON MON/TUE THE FORECAST AREA WILL BE BETWEEN
THE DEPARTING SYSTEM OFF THE EAST COAST AND YET ANOTHER SLOW
MOVING CLOSED UPPER LOW EJECTING EASTWARD OUT OF THE SOUTHWESTERN
STATES. EXPECT DRY WEATHER AND BELOW NORMAL TEMPERATURES WITH A
PERSISTENT NORTHERLY FLOW AND SURFACE HIGH PRESSURE RIDGING INTO
THE AREA FROM THE NORTH. THE SOUTHERN STREAM CLOSED LOW WILL BEGIN
TO OPEN AND DRIFT EASTWARD EVENTUALLY PHASING WITH NORTHERN STREAM
ENERGY BRINGING UNSETTLED WEATHER TO OUR AREA TUESDAY INTO
THURSDAY. LATEST GFS SHOWS DRY HIGH PRESSURE BUILDING IN FROM THE
WEST FRIDAY. TEMPERATURES GENERALLY AT OR JUST BELOW NORMAL
THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH AROUND 12Z THEN LOWER
CONFIDENCE AS MVFR RESTRICTIONS EXPECTED TO DEVELOP ALL TERMINALS
AS WIDESPREAD RAIN OVERSPREADS THE REGION ASSOCIATED WITH WARM
ADVECTION AS A WARM FRONT LIFTS NORTHWARD. LIGHT RAIN EXPECTED TO
IMPACT THE TERMINALS AFTER 12Z WITH MVFR CIGS/VSBYS SETTING IN
BETWEEN 14Z-16Z. LIGHT SOUTH TO SOUTHEASTERLY WINDS SHOULD
DEVELOP BY 12Z AND GRADUALLY SHIFT TO THE SOUTH AND EVENTUALLY
SOUTHWEST AS A WARM FRONT LIFTS NORTH THROUGH THE REGION THOUGH
THE DAY. SOME CONVECTION WITH STRONG THUNDERSTORMS POSSIBLE AFTER
16Z THROUGH 03Z-06Z TONIGHT BUT TIMING AND LOCATION STILL
UNCERTAIN SO WILL ONLY MENTION RAIN FOR NOW. CIGS SHOULD BECOME
MORE BROKEN OR SCATTERED LATE AFTERNOON AS THE WARM FRONT LIFTS
NORTHWARD BUT TIMING REMAINS UNCERTAIN.

LOW-LEVEL WIND SHEAR MAY BE AN ISSUE BEFORE WARM FRONTAL PASSAGE.
HIGH SHEAR AND INSTABILITY NEAR THE WARM FRONT MAY HELP SUPPORT
SEVERE THUNDERSTORMS WITH DAMAGING WIND AND HAIL SATURDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...SHOWERS AND THUNDERSTORMS WITH
ASSOCIATED RESTRICTIONS WILL BE POSSIBLE INTO SATURDAY EVENING.
BREEZY CONDITIONS POSSIBLE SUNDAY. NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KGSP 250745
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
345 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE NC
PIEDMONT THROUGH SUNRISE. LLVL MOISTURE SHOULD RAPIDLY INCREASE FROM
THE SOUTHWEST DURING THE MID TO LATE MORNING HOURS...RESULTING IN
MVFR CEILINGS AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO
THE AFTERNOON AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING.
BASED ON THE TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES
WILL DEVELOP DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL
HIGHLIGHT THE 22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE
EVENING...FORECAST SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND
MODEL CLOUDS ARE EASILY WITHIN IFR. WINDS DURING THE 6Z TAF WILL
REMAIN FROM THE SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A
WELL ORGANIZED SFC LOW OVER KY/TN.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. THE DEEP MOISTURE AND
FORCING WILL SPREAD SW TO NE...REACHING KHKY AROUND THE SAME PERIOD
AS KCLT. KHKY MAY DEVELOP WINDS FROM THE EAST-NORTHEAST AROUND
SUNRISE...PERSISTING THROUGH THE REST OF THE TAF PERIOD.
ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       HIGH 100%     MED   75%     MED   73%     MED   73%
KGSP       HIGH 100%     MED   66%     HIGH  86%     HIGH  83%
KAVL       HIGH 100%     MED   75%     MED   74%     HIGH 100%
KHKY       HIGH 100%     MED   69%     MED   73%     HIGH  81%
KGMU       HIGH 100%     MED   69%     MED   74%     HIGH  86%
KAND       HIGH 100%     MED   62%     HIGH  82%     HIGH  98%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED




000
FXUS62 KGSP 250745
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
345 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE NC
PIEDMONT THROUGH SUNRISE. LLVL MOISTURE SHOULD RAPIDLY INCREASE FROM
THE SOUTHWEST DURING THE MID TO LATE MORNING HOURS...RESULTING IN
MVFR CEILINGS AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO
THE AFTERNOON AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING.
BASED ON THE TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES
WILL DEVELOP DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL
HIGHLIGHT THE 22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE
EVENING...FORECAST SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND
MODEL CLOUDS ARE EASILY WITHIN IFR. WINDS DURING THE 6Z TAF WILL
REMAIN FROM THE SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A
WELL ORGANIZED SFC LOW OVER KY/TN.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. THE DEEP MOISTURE AND
FORCING WILL SPREAD SW TO NE...REACHING KHKY AROUND THE SAME PERIOD
AS KCLT. KHKY MAY DEVELOP WINDS FROM THE EAST-NORTHEAST AROUND
SUNRISE...PERSISTING THROUGH THE REST OF THE TAF PERIOD.
ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       HIGH 100%     MED   75%     MED   73%     MED   73%
KGSP       HIGH 100%     MED   66%     HIGH  86%     HIGH  83%
KAVL       HIGH 100%     MED   75%     MED   74%     HIGH 100%
KHKY       HIGH 100%     MED   69%     MED   73%     HIGH  81%
KGMU       HIGH 100%     MED   69%     MED   74%     HIGH  86%
KAND       HIGH 100%     MED   62%     HIGH  82%     HIGH  98%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED




000
FXUS62 KGSP 250745
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
345 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE NC
PIEDMONT THROUGH SUNRISE. LLVL MOISTURE SHOULD RAPIDLY INCREASE FROM
THE SOUTHWEST DURING THE MID TO LATE MORNING HOURS...RESULTING IN
MVFR CEILINGS AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO
THE AFTERNOON AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING.
BASED ON THE TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES
WILL DEVELOP DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL
HIGHLIGHT THE 22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE
EVENING...FORECAST SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND
MODEL CLOUDS ARE EASILY WITHIN IFR. WINDS DURING THE 6Z TAF WILL
REMAIN FROM THE SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A
WELL ORGANIZED SFC LOW OVER KY/TN.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. THE DEEP MOISTURE AND
FORCING WILL SPREAD SW TO NE...REACHING KHKY AROUND THE SAME PERIOD
AS KCLT. KHKY MAY DEVELOP WINDS FROM THE EAST-NORTHEAST AROUND
SUNRISE...PERSISTING THROUGH THE REST OF THE TAF PERIOD.
ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       HIGH 100%     MED   75%     MED   73%     MED   73%
KGSP       HIGH 100%     MED   66%     HIGH  86%     HIGH  83%
KAVL       HIGH 100%     MED   75%     MED   74%     HIGH 100%
KHKY       HIGH 100%     MED   69%     MED   73%     HIGH  81%
KGMU       HIGH 100%     MED   69%     MED   74%     HIGH  86%
KAND       HIGH 100%     MED   62%     HIGH  82%     HIGH  98%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED




000
FXUS62 KGSP 250745
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
345 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE NC
PIEDMONT THROUGH SUNRISE. LLVL MOISTURE SHOULD RAPIDLY INCREASE FROM
THE SOUTHWEST DURING THE MID TO LATE MORNING HOURS...RESULTING IN
MVFR CEILINGS AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO
THE AFTERNOON AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING.
BASED ON THE TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES
WILL DEVELOP DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL
HIGHLIGHT THE 22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE
EVENING...FORECAST SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND
MODEL CLOUDS ARE EASILY WITHIN IFR. WINDS DURING THE 6Z TAF WILL
REMAIN FROM THE SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A
WELL ORGANIZED SFC LOW OVER KY/TN.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. THE DEEP MOISTURE AND
FORCING WILL SPREAD SW TO NE...REACHING KHKY AROUND THE SAME PERIOD
AS KCLT. KHKY MAY DEVELOP WINDS FROM THE EAST-NORTHEAST AROUND
SUNRISE...PERSISTING THROUGH THE REST OF THE TAF PERIOD.
ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       HIGH 100%     MED   75%     MED   73%     MED   73%
KGSP       HIGH 100%     MED   66%     HIGH  86%     HIGH  83%
KAVL       HIGH 100%     MED   75%     MED   74%     HIGH 100%
KHKY       HIGH 100%     MED   69%     MED   73%     HIGH  81%
KGMU       HIGH 100%     MED   69%     MED   74%     HIGH  86%
KAND       HIGH 100%     MED   62%     HIGH  82%     HIGH  98%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED




000
FXUS62 KGSP 250745
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
345 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE NC
PIEDMONT THROUGH SUNRISE. LLVL MOISTURE SHOULD RAPIDLY INCREASE FROM
THE SOUTHWEST DURING THE MID TO LATE MORNING HOURS...RESULTING IN
MVFR CEILINGS AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO
THE AFTERNOON AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING.
BASED ON THE TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES
WILL DEVELOP DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL
HIGHLIGHT THE 22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE
EVENING...FORECAST SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND
MODEL CLOUDS ARE EASILY WITHIN IFR. WINDS DURING THE 6Z TAF WILL
REMAIN FROM THE SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A
WELL ORGANIZED SFC LOW OVER KY/TN.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. THE DEEP MOISTURE AND
FORCING WILL SPREAD SW TO NE...REACHING KHKY AROUND THE SAME PERIOD
AS KCLT. KHKY MAY DEVELOP WINDS FROM THE EAST-NORTHEAST AROUND
SUNRISE...PERSISTING THROUGH THE REST OF THE TAF PERIOD.
ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       HIGH 100%     MED   75%     MED   73%     MED   73%
KGSP       HIGH 100%     MED   66%     HIGH  86%     HIGH  83%
KAVL       HIGH 100%     MED   75%     MED   74%     HIGH 100%
KHKY       HIGH 100%     MED   69%     MED   73%     HIGH  81%
KGMU       HIGH 100%     MED   69%     MED   74%     HIGH  86%
KAND       HIGH 100%     MED   62%     HIGH  82%     HIGH  98%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED




000
FXUS62 KGSP 250745
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
345 AM EDT SAT APR 25 2015

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE EAST FROM THE CENTRAL PLAINS
STATES INTO THE SOUTHEAST TODAY. A WARM FRONT WILL LINGER OVER OUR
AREA FOR MUCH OF THE WEEKEND PROVIDING A FOCUS OF SHOWERS AND A FEW
STORMS. DRY HIGH PRESSURE WILL MOVE IN AGAIN FOR THE START OF THE
WORK WEEK...WITH ANOTHER LOW PRESSURE SYSTEM CROSSING THE SOUTHEAST
BY MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. FURTHER WEST...WATER VAPOR LOOP INDICATED A
CLOSED MID LEVEL LOW OVER THE CENTRAL PLAINS...DRIFTING TO THE EAST-
NORTHEAST. SOUTH EAST OF THE MID LEVEL LOW...A LARGE BAND OF
CONVECTION WAS TRACKING EAST ACROSS NRN MS/AL. THIS ACTIVITY LARGELY
ORIGINATED NEAR THE SFC WARM FRONT AND WITHIN A BELT OF UPPER JET
DIVERGENCE. HOWEVER...THE CONVECTION IS TRACKING QUICKLY
EAST...OUTPACING THE MOST SUPPORTIVE ENVIRONMENT. AS A
RESULT...RECENT IR SATELLITE IMAGES INDICATED A STEADY WARMING TREND
OF CLOUD TOP TEMPERATURES...LIGHTNING COUNTS WERE ALSO DECREASING.
THESE WEAKENING TRENDS MATCH UP WELL WITH THE CONVECTION ALLOWING
MODELS...WHICH INDICATES THAT THE DEEP CONVECTION WILL STEADY WEAKEN
AS IT TRACKS EAST ALONG THE I-20 CORRIDOR. A LARGE AREA RAIN IS
FORECAST TO OCCUR ACROSS THE CWA THIS MORNING...PRIMARILY WEST OF I-
26. I WILL INDICATE THE RAINFALL TO FALL FROM SHRA WITH SOME
EMBEDDED THUNDERSTORMS. SEVERE WEATHER ASSOCIATED WITH THE MORNING
ACTIVITY APPEARS MINIMAL.

BY MID DAY...THE BULK OF THE DECAYING CONVECTION IS EXPECTED TO PUSH
EAST OF THE REGION. DURING THE AFTERNOON...THE PRIMARY CHALLENGE
WILL BE THE PLACEMENT OF A WEAK IN-SITU AREA OF COLD AIR DAMMING.
BASED OFF THE LATEST NAM...I WILL INDICATE THAT THE NC FOOTHILLS AND
NRN PIEDMONT WILL SEE LIGHT NE WINDS AND THICK AND PERSISTENT CLOUD
COVER. HOWEVER...AREAS TO THE SOUTH AND WEST MAY EXPERIENCE DEEP
SOUTHWEST FLOW AND DIURNALLY WARMING TEMPERATURES. IN FACT...THE NAM
SHOWS A HORSESHOE SHAPED AREA OF SB CAPE ACROSS THE MTNS AND
PORTIONS OF THE UPPER SAVANNAH RIVER VALLEY AND SC UPSTATE EAST OF I-
85. IN ADDITION...IMPRESSIVE SHEAR VALUES DEVELOP WITHIN THE
UNSTABLE AREAS...PEAKING DURING THE MID EVENING HOURS. HEILICITY
BETWEEN SFC-1KM IS FORECAST TO RANGE AROUND 300 M2/S2...EHI VALUES
FROM 2.5-4...AND SWEAT VALUES GENERALLY AROUND 350. HOWEVER...CIN
VALUES FROM THE NAM SOUNDING RANGE FROM 30 TO 50 J/KG THIS EVENING.
MODELS INDICATE THAT CONVECTION COVERAGE WILL BE AT A MINIMUM DURING
THE LATE AFTERNOON AND EVENING.

TONIGHT...A WELL DEVELOPED SFC LOW WILL SLIDE EAST ACROSS
KY/TN...CROSSING THE SOUTHERN APPALACHIANS AROUND MIDNIGHT. AT THE
MID LEVELS...THE CLOSED LOW FROM THIS MORNING WILL DEVELOP INTO A
POSITIVE TILTED TROF AND WILL RIPPLE EAST OVER THE SFC LOW. NEAR TERM
MODELS INDICATE THAT A MCS WILL LIKELY DEVELOP AHEAD OF THE LOW
CENTER...STEERING FLOW SHOULD RESULT IN THE SYSTEM TO TRACK EAST-
SOUTHEAST TONIGHT. BASED ON EXPERIENCE...I ANTICIPATE THAT THE MCS
SPEED WILL BE GREATER THAN THE MODEL CONSENSUS. THIS ADJUSTMENT
WOULD PLACE THE MCS OVER THE NC MTNS DURING THE EARLY MORNING HOURS
SUNDAY. BY THAT TIME...THE GREATEST SHEAR AND INSTABILITY VALUES
HAVE ENDED...LEAVING WEAK TO MODERATE VALUES ACROSS THE MTNS AND
SC/GA LINE. THIS WILL LIKELY SUPPORT THE MCS REACHING THE MTNS...BUT
STEADILY WEAKENING AS THE ACTIVITY APPROACHES THE FOOTHILLS.
HOWEVER...LOW WBZ AND LINGERING SHEAR AND INSTABILITY WOULD LIKELY
YIELD SEVERAL SEVERE WIND AND HAIL EVENTS AS THE CONVECTION ARRIVES.
WE WILL CONTINUE TO HIGHLIGHT IN THE HWO.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...THE SHORT TERM BEGINS WITH TRYING TO TIME
THE EXIT OF THE SURFACE LOW OFF THE CAROLINA COAST. SHORT TERM
GUIDANCE IN PRETTY GOOD AGREEMENT WITH EAST-WEST ELONGATED TROUGH
STRETCHING WESTWARD INTO OUR AREA FROM THE CENTER OF THE SURFACE LOW
IN THE ATLANTIC AT THE START OF THE SHORT TERM. SPLIT FLOW PATTERN
CONTINUES ALOFT...WITH SHORTWAVE ALSO PUSHING OFFSHORE AND MEAN
TROUGH TAKING OVER. STROGN DOWNSLOPING COMPONENT ON SUNDAY WILL LEAD
TO HIGHS INCREASING TO WELL ABOVE NORMAL VALUES ACROSS THE UPSTATE
AND PORTIONS OF THE PIEDMONT BEFORE THE ACTUAL COLD FRONT PUSHES
THROUGH...THOUGH ESPECIALLY THE NORTHERN MOUNTAINS WILL BE ON THE
COOL SIDE. MIDLEVEL MOISTURE HANGS ON ENOUGH TO KEEP SOME CLOUDINESS
AND PERHAPS SOME LINGERING SHOWERS ACROSS THE AREA THROUGH THE EARLY
PART OF THE DAY...BUT WE SHOULD START SEEING A CLEARING TREND
OVERNIGHT SUNDAY NIGHT INTO MONDAY.

SHOULD SEE A PRETTY MARKED DIFFERENCE IN HIGHS ON MONDAY BEHIND THE
FRONT WITH DEEP-LAYER CAA ACROSS THE AREA...THOUGH THE MAGNITUDE OF
THE CAA DECREASES THROUGH THE DAY. ANOTHER SHORTWAVE AXIS PUSHES
DOWN THE UPPER TROUGH...STILL FIRMLY IN PLACE ACROSS THE EASTERN
PORTION OF THE COUNTRY...LATE MONDAY INTO EARLY TUESDAY. THIS TROUGH
MANAGES TO FINALLY PUSH THE DEEP UPPER LOW FARTHER OUT INTO THE
ATLANTIC BUT WILL USHER IN COOLER HIGH PRESSURE FOR THE BEGINNING OF
THE EXTENDED.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM SATURDAY...HIGH PRESSURE CENTERED ACROSS THE NORTHERN
PLAINS AND SOUTHERN CANADA WILL BE RIDGING INTO THE SOUTHEAST AS WE
START THE EXTENDED...WITH THE AFOREMENTIONED UPPER SHORTWAVE DIGGING
AROUND THE WESTERN PERIPHERY OF THE LOW OVER THE NORTHWEST ATLANTIC.
MEANWHILE...A CUTOFF LOW OVER THE SOUTHERN PLAINS WILL BEGIN TO
SLIDE EAST AS THE WAVETRAIN FINALLY PROGRESSES. HEIGHT FALLS AHEAD
OF THE UPPER LOW WILL INDUCE CYCLOGENESIS ACROSS THE NORTHERN
GULF...SPREADING MOISTURE INTO THE LOWER MISSISSIPPI VALLEY AND
SOUTHEAST THROUGH THE MIDDLE OF THE WORK WEEK. BOTH THE GFS AND
ECMWF HAVE BEEN TRENDING THE SURFACE LOW FARTHER SOUTH WITH
SUBSEQUENT RUNS AND FOR THIS MORNING IT IS LITTLE DIFFERENT...WITH
THE LOW PUSHING EAST ACROSS THE FLORIDA PANHANDLE UNTIL WEDNESDAY
NIGHT AND ONLY LIFTING SLIGHTLY INTO SOUTH GEORGIA. THE ECMWF HAS
SPED THE SYSTEM UP WITH A DEEPER NORTH-SOUTH ELONGATED TROUGH PHASED
WITH THE GREAT LAKES TROUGH...WHEREAS THE GFS HAS TRENDED A LITTLE
SLOWER AND TAKES A LITTLE LONGER TO PHASE THE FORMER CUTOFF LOW WITH
THE LARGER SYSTEM. IN ANY CASE...CLOUDY AND COOL CONDITIONS WILL
PREVAIL THROUGH THE MIDDLE OF THE WEEK...WITH HIGHS ESPECIALLY
WEDNESDAY A GOOD 10 DEGREES BELOW SEASONAL NORMALS. VERY HARD TO
TELL AT THIS POINT...WITH THE DIFFERENCES IN THE MODELS PLUS LACK OF
RUN-TO-RUN CONTINUITY...WHEN THE PRECIP WILL MOVE OUT. IN GENERAL
HAVE CONTINUED TREND OF MID-RANGE POPS...WITH A FEW LIKELIES SOUTH
ON WEDNESDAY...WITH A SLOW DRYING TREND THURSDAY INTO THURSDAY
EVENING. MORE DIVERGENCE IN EXTENDED GUIDANCE AT THE END OF THE
PERIOD BUT OVERALL EXPECT A DRYING TREND TOWARD THE END OF THE WORK
WEEK WITH TEMPERATURES TRENDING BACK TOWARDS CLIMO.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE NC
PIEDMONT THROUGH SUNRISE. LLVL MOISTURE SHOULD RAPIDLY INCREASE FROM
THE SOUTHWEST DURING THE MID TO LATE MORNING HOURS...RESULTING IN
MVFR CEILINGS AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO
THE AFTERNOON AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING.
BASED ON THE TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES
WILL DEVELOP DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL
HIGHLIGHT THE 22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE
EVENING...FORECAST SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND
MODEL CLOUDS ARE EASILY WITHIN IFR. WINDS DURING THE 6Z TAF WILL
REMAIN FROM THE SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A
WELL ORGANIZED SFC LOW OVER KY/TN.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. THE DEEP MOISTURE AND
FORCING WILL SPREAD SW TO NE...REACHING KHKY AROUND THE SAME PERIOD
AS KCLT. KHKY MAY DEVELOP WINDS FROM THE EAST-NORTHEAST AROUND
SUNRISE...PERSISTING THROUGH THE REST OF THE TAF PERIOD.
ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       HIGH 100%     MED   75%     MED   73%     MED   73%
KGSP       HIGH 100%     MED   66%     HIGH  86%     HIGH  83%
KAVL       HIGH 100%     MED   75%     MED   74%     HIGH 100%
KHKY       HIGH 100%     MED   69%     MED   73%     HIGH  81%
KGMU       HIGH 100%     MED   69%     MED   74%     HIGH  86%
KAND       HIGH 100%     MED   62%     HIGH  82%     HIGH  98%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...TDP
NEAR TERM...NED
SHORT TERM...TDP
LONG TERM...TDP
AVIATION...NED



000
FXUS62 KGSP 250627
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
227 AM EDT SAT APR 25 2015

.SYNOPSIS...
COOL AND DRY HIGH PRESSURE MOVES OUT OVER THE ATLANTIC
TONIGHT AS LOW PRESSURE MOVES EAST FROM THE CENTRAL PLAINS STATES. A
WARM FRONT WILL LINGER OVER OUR AREA FOR MUCH OF THE WEEKEND
PROVIDING A FOCUS OF SHOWERS AND A FEW STORMS. DRY HIGH PRESSURE
WILL MOVE IN AGAIN FOR THE START OF THE WORK WEEK...WITH ANOTHER LOW
PRESSURE SYSTEM CROSSING THE SOUTHEAST BY MIDWEEK.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 225 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. LLVL MOISTURE SHOULD RAPIDLY INCREASE FROM THE
SOUTHWEST DURING THE MID TO LATE MORNING HOURS...RESULTING IN MVFR
CEILINGS AND LIGHT SHRA. I WILL ISSUE A QUICK UPDATE TO ADJUST
TEMPERATURES TO OBSERVATIONS...THEN POPULATE TEMPERATURES AND
DEWPOINTS THROUGH TONIGHT WITH A 50/50 BLEND OF PREVIOUS FORECAST
AND NAM.

AS OF 1040 PM EDT FRIDAY...SHIELD OF UPGLIDE INDUCED PRECIP
CONTINUES TO SPREAD ACROSS THE LOWER OHIO AND TENNESSEE VALLEYS THIS
EVENING.  LATEST NAM INDICATES THIS TREND IS STILL EXPECTED TO
CONTINUE ALL THE WHILE ADVECTING EAST OVERNIGHT.  DESPITE LIGHT
RETURNS ON RADAR EXPECTING THE DRY BOUNDARY LAYER TO WIN OVER FOR AT
LEAST A FEW MORE HOURS BEFORE ANY PRECIP FALLS TO THE SFC.
THUS...BACKED POPS DOWN OVER THE NEXT HOUR OR TWO...BUT THEN
CONTINUED WITH THE PREVIOUS TRENDS WITH ONE ADDITIONAL CHANGE.  PER
LATEST CAM GUID BLEND...OPTED TO INCREASE POPS A BIT SOONER
OVERNIGHT ACROSS THE UPPER SAVANNAH RIVER VALLEY AND THE LAKELANDS
REGION.  THIS CHANGE YIELDED LIKELY LEVEL POPS BY DAYBREAK.  POPS
ARE STILL FCST TO EXPAND FURTHER EAST THROUGH MID MORNING WITH
CATEGORICAL POPS PREVAILING ATOP THE ENTIRE REGION BY LATE MORNING.
OTHERWISE...NO SIG CHANGES WITH THIS UPDATE.

PREVIOUS DISCUSSION...

AT 230 PM EDT FRIDAY...AN UPPER RIDGE WAS LOCATED OVER THE MS RIVER
VALLEY THIS AFTERNOON...WITH TROUGHS OFF THE EAST COAST AND OVER THE
ROCKIES. SURFACE HIGH PRESSURE CENTERED OVER THE OH RIVER VALLEY
EXTENDED TO THE CAROLINA AND GA COASTS THIS AFTERNOON. MEANWHILE A
COLD FRONT WAS LOCATED OVER CENTRAL FL AND THE NW GULF OF MEXICO.
CLOUDS COVER REMAINED LIMITED MAINLY TO THE MS RIVER VALLEY...WITH
SOME HIGH LEVEL CLOUDS SPILLING OVER THE RIDGE IN SW TN AND N GA.

THE UPPER RIDGE IS EXPECTED TO PROGRESS TO THE SOUTHERN APPALACHIANS
BY SATURDAY MORNING...WHILE AN UPPER LOW CLOSES OFF IN THE TROUGH
UPSTREAM AND CROSSES THE CENTRAL PLAINS. THIS LOW FILLS NEAR THE
SOUTHERN GREAT LAKES LATE SATURDAY...WHILE THE UPPER RIDGE
DEAMPLIFIES...LEADING TO ZONAL FLOW OVER THE SE.

THE SURFACE BOUNDARY IN THE GULF STARTS TO RETURN N AS A WARM FRONT
OVERNIGHT...AND MOIST SOUTHWESTERLY ISENTROPIC UPGLIDE OVER THE
BOUNDARY WILL SUPPORT LOWERING CLOUDS AND PRECIPITATION OVER OUR
AREA. A LIGHT LOW LEVEL SOUTHERLY FLOW WILL ADD SOME UPSLOPE FLOW
INTO THE SOUTHERN APPALACHIANS. UPGLIDE MAXIMIZES BY MIDDAY
SATURDAY...WHEN THE GREATEST PRECIPITATION IS EXPECTED. RAINFALL
AMOUNTS COULD EXCEED ONE INCH IN THE UPPER SAVANNAH RIVER VALLEY AND
THE SOUTH FACING BLUE RIDGE ESCARPMENT ON SATURDAY...BUT AT THIS
TIME FLOODING APPEARS TO BE A LIMITED HAZARD BASED ON THE SOMEWHAT
EXTENDED DURATION OF THE EVENT.

INSTABILITY WILL INCREASE ON SATURDAY...BECOMING INCREASINGLY
SUFFICIENT FOR THUNDERSTORMS IN THE AFTERNOON OVER THE S AND W OF
THE AREA. WITH SHEAR INCREASING...THE CHANCE OF SEVERE THUNDERSTORMS
WILL INCREASE AS WELL. TEMPERATURES WILL EXHIBIT A LIMITED DIURNAL
RANGE...AS CLOUD COVER AND INCREASING MOISTURE LIMIT COOLING AND
HEATING.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 205 PM FRIDAY...THE MAIN SHORT TERM CONCERN REVOLVES AROUND
THE CONTINUED POTENTIAL FOR STRONG/SEVERE CONVECTION ACROSS THE AREA
INTO SATURDAY NIGHT. UNFORTUNATELY...CONSIDERING THE RATHER WEAKLY
FORCED NATURE OF THE ENVIRONMENT...CONVECTIVE TRENDS ACROSS OUR AREA
ARE NONE-TOO-OBVIOUS. IT SEEMS A VIRTUAL CERTAINTY THAT ORGANIZED
CONVECTION WILL DEVELOP DURING SAT AFTERNOON/EVENING ACROSS THE OHIO
VALLEY. HOWEVER...THERE WILL BE COMPETITION BETWEEN THE MEAN CLOUD-
BEARING FLOW (DUE WESTERLY) AND THE ORIENTATION OF INSTABILITY AND
LOW LEVEL FORCING (WARM FRONT/CAPE AXIS EXTENDING SOUTHEAST FROM THE
OHIO VALLEY) IN DETERMINING THE TRACK OF ANY ORGANIZED CONVECTIVE
COMPLEX. IN FACT...THERE IS NO CLEAR CONSENSUS AMONG THE LATEST
MESOSCALE AND SHORT TERM MODELS IN THIS REGARD. THE HIGHEST POPS
(PRIMARILY LIKELY) FOR SAT EVENING WILL BE MAINTAINED ACROSS THE
WESTERN MTNS AND OUR FAR NORTHERN ZONES. ASSUMING AN MCS DOES MANAGE
TO DROP INTO THE CWA TOMORROW EVENING...A CONSENSUS OF MODEL
INSTABILITY PROGS INDICATES IT WILL NOT FIND THE MOST ACCOMMODATING
ENVIRONMENT ACROSS OUR NORTHERN ZONES...AS ESSENTIALLY NO MODEL
DEPICTS POSITIVE SURFACE-BASED BUOYANCY DEVELOPING NORTH OF
(ROUGHLY) I-85 IN THE PIEDMONT/FOOTHILLS. (THERE IS HOWEVER A DECENT
AMOUNT OF ELEVATED CAPE DEPICTED). THEREFORE...OUTSIDE OF THE
POTENTIAL FOR A DOWNBURST-PRODUCING MCS TO SLAM INTO THE NC MTNS
BEFORE WEAKENING AND/OR BECOMING LESS ROOTED IN THE BOUNDARY
LAYER...THE SEVERE WEATHER POTENTIAL ACROSS OUR NORTHERN ZONES
APPEARS LESS THAN STELLAR.

THE MORE INTERESTING ACTION TOMORROW NIGHT COULD BE FARTHER SOUTH...
AS WARM FRONT SLOWLY LIFTS NORTH AND SPREADS UNSTABLE AIR INTO OUR
SOUTHERN PIEDMONT/SOUTHWEST MTNS AREA. SOME OF THE MESO-MODELS ARE
HINTING AT THE POTENTIAL FOR SCATTERED DISCRETE CONVECTION TO
DEVELOP WITHIN A DESTABILIZING/RECOVERING AIR MASS ACROSS NORTH
GEORGIA AND THE TENN VALLEY BY LATE AFTERNOON...WHICH COULD MAKE A
RUN INTO THE CWA DURING THE EVENING. AGAIN...THIS IS FAR FROM A SLAM
DUNK IN LIGHT OF A GENERALLY WEAKLY FORCED WARM SECTOR ENVIRONMENT.
HOWEVER...THE POTENTIAL IS CERTAINLY THERE...AND IN LIGHT OF THE
RATHER VOLATILE ENVIRONMENTAL WARM SECTOR CONDITIONS THAT ARE
EXPECTED (SBCAPE 1500-2000 J/KG...DEEP LAYER SHEAR OF 70
KTS)...SUPERCELLS WOULD BE LIKELY...WITH PERHAPS A THREAT FOR AN
ISOLATED TORNADO NEAR THE WARM FRONT.

WEAKENING SURFACE LOW IS EXPECTED TO TRACK NEAR THE NC/VA LINE SAT
NIGHT INTO SUNDAY...WITH TRAILING COLD FRONT MOVING ACROSS THE AREA
DURING THE MORNING INTO THE AFTERNOON. A BIT OF SBCAPE MAY CREEP
INTO THE PIEDMONT AHEAD OF THE FRONT BY EARLY AFTERNOON...WHILE NW
FLOW COULD SUPPORT SHOWER DEVELOPMENT ACROSS THE FAR WESTERN MTNS.
POPS FOR SCATTERED CONVECTION ARE THEREFORE WARRANTED IN MAINLY
THOSE AREAS. THE REMAINDER OF THE PERIOD WILL BE QUIET AND DRY...
WITH TEMPS ABOUT 5 DEGREES BELOW CLIMO.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 145 PM FRIDAY...THE MODEL GUIDANCE HAS CONTINUED THE TREND OF
DELAYING THE ARRIVAL OF THE NEXT SYSTEM DURING THE MIDDLE OF NEXT
WEEK. THE LATEST GFS KEEPS THE UPPER RIDGE AXIS TO THE WEST MONDAY
NIGHT AND DOES NOT MAKE IT INTO THE WESTERN CAROLINAS UNTIL MAYBE
VERY LATE IN THE DAY ON TUESDAY. THE 00Z RUN OF THE ECMWF WAS
SIMILAR IN SHOWING LITTLE SUPPORT OR MOISTURE FOR PRECIP UNTIL MAYBE
LATE TUESDAY AFTERNOON. WITH THAT IN MIND...WILL IMPOSE YET ANOTHER
DELAY WITH THE ARRIVAL OF PRECIP CHANCES FROM THE SOUTHWEST UNTIL
LATE TUESDAY AFTERNOON...AND WILL SLOW THE INCREASE IN PRECIP
CHANCES TUESDAY NIGHT. NOT MUCH IN THE NEW MODEL GUIDANCE TO SUGGEST
ANY CHANGES TO THE FCST...UNLESS THE 12Z RUN OF THE ECMWF TRENDS
FASTER LIKE THE GFS. HOWEVER...IN SPITE OF THE MODEL DIFFERENCES
WITH THE EVOLUTION OF THE UPPER LOW AND TRACK/STRENGTH OF THE
SURFACE LOW MOVING ACROSS THE DEEP SOUTH ON WEDNESDAY AND
THURSDAY... THE WEAKER/FASTER GFS STILL MANAGES TO HOLD ONTO SOME
LIGHT PRECIP ACROSS THE WESTERN CAROLINAS AS ITS SHEARING/POSITIVELY
TILTED UPPER TROF MOVES OVERHEAD THRU THURSDAY EVENING. THUS...FEW
CHANGES WERE MADE. PRECIP PROB WAS KEPT IN THE CHANCE RANGE AND
TEMPS WERE KEPT SEASONALLY COOL...ABOUT 10 DEG BELOW NORMAL. THE
MODEL SOLUTIONS COME INTO AGREEMENT BY THURSDAY NIGHT WITH MOVING
THE PRECIP OUT. FRIDAY SHOULD BE DRY WITH HIGH PRESSURE BUILDING IN
FROM THE WEST AND TEMPS STARTING A REBOUND TOWARD NORMAL.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE NC
PIEDMONT THROUGH SUNRISE. LLVL MOISTURE SHOULD RAPIDLY INCREASE FROM
THE SOUTHWEST DURING THE MID TO LATE MORNING HOURS...RESULTING IN
MVFR CEILINGS AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO
THE AFTERNOON AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING.
BASED ON THE TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES
WILL DEVELOP DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL
HIGHLIGHT THE 22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE
EVENING...FORECAST SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND
MODEL CLOUDS ARE EASILY WITHIN IFR. WINDS DURING THE 6Z TAF WILL
REMAIN FROM THE SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A
WELL ORGANIZED SFC LOW OVER KY/TN.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. THE DEEP MOISTURE AND
FORCING WILL SPREAD SW TO NE...REACHING KHKY AROUND THE SAME PERIOD
AS KCLT. KHKY MAY DEVELOP WINDS FROM THE EAST-NORTHEAST AROUND
SUNRISE...PERSISTING THROUGH THE REST OF THE TAF PERIOD.
ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       HIGH 100%     MED   79%     MED   72%     HIGH  80%
KGSP       HIGH 100%     MED   68%     HIGH  87%     HIGH  83%
KAVL       HIGH 100%     MED   77%     MED   75%     HIGH 100%
KHKY       HIGH 100%     MED   73%     MED   72%     HIGH  85%
KGMU       HIGH 100%     MED   71%     MED   77%     HIGH  83%
KAND       HIGH 100%     MED   68%     MED   78%     HIGH  96%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...JDL
LONG TERM...PM
AVIATION...NED



000
FXUS62 KGSP 250627
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
227 AM EDT SAT APR 25 2015

.SYNOPSIS...
COOL AND DRY HIGH PRESSURE MOVES OUT OVER THE ATLANTIC
TONIGHT AS LOW PRESSURE MOVES EAST FROM THE CENTRAL PLAINS STATES. A
WARM FRONT WILL LINGER OVER OUR AREA FOR MUCH OF THE WEEKEND
PROVIDING A FOCUS OF SHOWERS AND A FEW STORMS. DRY HIGH PRESSURE
WILL MOVE IN AGAIN FOR THE START OF THE WORK WEEK...WITH ANOTHER LOW
PRESSURE SYSTEM CROSSING THE SOUTHEAST BY MIDWEEK.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 225 AM...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE
CWA THROUGH SUNRISE. LLVL MOISTURE SHOULD RAPIDLY INCREASE FROM THE
SOUTHWEST DURING THE MID TO LATE MORNING HOURS...RESULTING IN MVFR
CEILINGS AND LIGHT SHRA. I WILL ISSUE A QUICK UPDATE TO ADJUST
TEMPERATURES TO OBSERVATIONS...THEN POPULATE TEMPERATURES AND
DEWPOINTS THROUGH TONIGHT WITH A 50/50 BLEND OF PREVIOUS FORECAST
AND NAM.

AS OF 1040 PM EDT FRIDAY...SHIELD OF UPGLIDE INDUCED PRECIP
CONTINUES TO SPREAD ACROSS THE LOWER OHIO AND TENNESSEE VALLEYS THIS
EVENING.  LATEST NAM INDICATES THIS TREND IS STILL EXPECTED TO
CONTINUE ALL THE WHILE ADVECTING EAST OVERNIGHT.  DESPITE LIGHT
RETURNS ON RADAR EXPECTING THE DRY BOUNDARY LAYER TO WIN OVER FOR AT
LEAST A FEW MORE HOURS BEFORE ANY PRECIP FALLS TO THE SFC.
THUS...BACKED POPS DOWN OVER THE NEXT HOUR OR TWO...BUT THEN
CONTINUED WITH THE PREVIOUS TRENDS WITH ONE ADDITIONAL CHANGE.  PER
LATEST CAM GUID BLEND...OPTED TO INCREASE POPS A BIT SOONER
OVERNIGHT ACROSS THE UPPER SAVANNAH RIVER VALLEY AND THE LAKELANDS
REGION.  THIS CHANGE YIELDED LIKELY LEVEL POPS BY DAYBREAK.  POPS
ARE STILL FCST TO EXPAND FURTHER EAST THROUGH MID MORNING WITH
CATEGORICAL POPS PREVAILING ATOP THE ENTIRE REGION BY LATE MORNING.
OTHERWISE...NO SIG CHANGES WITH THIS UPDATE.

PREVIOUS DISCUSSION...

AT 230 PM EDT FRIDAY...AN UPPER RIDGE WAS LOCATED OVER THE MS RIVER
VALLEY THIS AFTERNOON...WITH TROUGHS OFF THE EAST COAST AND OVER THE
ROCKIES. SURFACE HIGH PRESSURE CENTERED OVER THE OH RIVER VALLEY
EXTENDED TO THE CAROLINA AND GA COASTS THIS AFTERNOON. MEANWHILE A
COLD FRONT WAS LOCATED OVER CENTRAL FL AND THE NW GULF OF MEXICO.
CLOUDS COVER REMAINED LIMITED MAINLY TO THE MS RIVER VALLEY...WITH
SOME HIGH LEVEL CLOUDS SPILLING OVER THE RIDGE IN SW TN AND N GA.

THE UPPER RIDGE IS EXPECTED TO PROGRESS TO THE SOUTHERN APPALACHIANS
BY SATURDAY MORNING...WHILE AN UPPER LOW CLOSES OFF IN THE TROUGH
UPSTREAM AND CROSSES THE CENTRAL PLAINS. THIS LOW FILLS NEAR THE
SOUTHERN GREAT LAKES LATE SATURDAY...WHILE THE UPPER RIDGE
DEAMPLIFIES...LEADING TO ZONAL FLOW OVER THE SE.

THE SURFACE BOUNDARY IN THE GULF STARTS TO RETURN N AS A WARM FRONT
OVERNIGHT...AND MOIST SOUTHWESTERLY ISENTROPIC UPGLIDE OVER THE
BOUNDARY WILL SUPPORT LOWERING CLOUDS AND PRECIPITATION OVER OUR
AREA. A LIGHT LOW LEVEL SOUTHERLY FLOW WILL ADD SOME UPSLOPE FLOW
INTO THE SOUTHERN APPALACHIANS. UPGLIDE MAXIMIZES BY MIDDAY
SATURDAY...WHEN THE GREATEST PRECIPITATION IS EXPECTED. RAINFALL
AMOUNTS COULD EXCEED ONE INCH IN THE UPPER SAVANNAH RIVER VALLEY AND
THE SOUTH FACING BLUE RIDGE ESCARPMENT ON SATURDAY...BUT AT THIS
TIME FLOODING APPEARS TO BE A LIMITED HAZARD BASED ON THE SOMEWHAT
EXTENDED DURATION OF THE EVENT.

INSTABILITY WILL INCREASE ON SATURDAY...BECOMING INCREASINGLY
SUFFICIENT FOR THUNDERSTORMS IN THE AFTERNOON OVER THE S AND W OF
THE AREA. WITH SHEAR INCREASING...THE CHANCE OF SEVERE THUNDERSTORMS
WILL INCREASE AS WELL. TEMPERATURES WILL EXHIBIT A LIMITED DIURNAL
RANGE...AS CLOUD COVER AND INCREASING MOISTURE LIMIT COOLING AND
HEATING.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 205 PM FRIDAY...THE MAIN SHORT TERM CONCERN REVOLVES AROUND
THE CONTINUED POTENTIAL FOR STRONG/SEVERE CONVECTION ACROSS THE AREA
INTO SATURDAY NIGHT. UNFORTUNATELY...CONSIDERING THE RATHER WEAKLY
FORCED NATURE OF THE ENVIRONMENT...CONVECTIVE TRENDS ACROSS OUR AREA
ARE NONE-TOO-OBVIOUS. IT SEEMS A VIRTUAL CERTAINTY THAT ORGANIZED
CONVECTION WILL DEVELOP DURING SAT AFTERNOON/EVENING ACROSS THE OHIO
VALLEY. HOWEVER...THERE WILL BE COMPETITION BETWEEN THE MEAN CLOUD-
BEARING FLOW (DUE WESTERLY) AND THE ORIENTATION OF INSTABILITY AND
LOW LEVEL FORCING (WARM FRONT/CAPE AXIS EXTENDING SOUTHEAST FROM THE
OHIO VALLEY) IN DETERMINING THE TRACK OF ANY ORGANIZED CONVECTIVE
COMPLEX. IN FACT...THERE IS NO CLEAR CONSENSUS AMONG THE LATEST
MESOSCALE AND SHORT TERM MODELS IN THIS REGARD. THE HIGHEST POPS
(PRIMARILY LIKELY) FOR SAT EVENING WILL BE MAINTAINED ACROSS THE
WESTERN MTNS AND OUR FAR NORTHERN ZONES. ASSUMING AN MCS DOES MANAGE
TO DROP INTO THE CWA TOMORROW EVENING...A CONSENSUS OF MODEL
INSTABILITY PROGS INDICATES IT WILL NOT FIND THE MOST ACCOMMODATING
ENVIRONMENT ACROSS OUR NORTHERN ZONES...AS ESSENTIALLY NO MODEL
DEPICTS POSITIVE SURFACE-BASED BUOYANCY DEVELOPING NORTH OF
(ROUGHLY) I-85 IN THE PIEDMONT/FOOTHILLS. (THERE IS HOWEVER A DECENT
AMOUNT OF ELEVATED CAPE DEPICTED). THEREFORE...OUTSIDE OF THE
POTENTIAL FOR A DOWNBURST-PRODUCING MCS TO SLAM INTO THE NC MTNS
BEFORE WEAKENING AND/OR BECOMING LESS ROOTED IN THE BOUNDARY
LAYER...THE SEVERE WEATHER POTENTIAL ACROSS OUR NORTHERN ZONES
APPEARS LESS THAN STELLAR.

THE MORE INTERESTING ACTION TOMORROW NIGHT COULD BE FARTHER SOUTH...
AS WARM FRONT SLOWLY LIFTS NORTH AND SPREADS UNSTABLE AIR INTO OUR
SOUTHERN PIEDMONT/SOUTHWEST MTNS AREA. SOME OF THE MESO-MODELS ARE
HINTING AT THE POTENTIAL FOR SCATTERED DISCRETE CONVECTION TO
DEVELOP WITHIN A DESTABILIZING/RECOVERING AIR MASS ACROSS NORTH
GEORGIA AND THE TENN VALLEY BY LATE AFTERNOON...WHICH COULD MAKE A
RUN INTO THE CWA DURING THE EVENING. AGAIN...THIS IS FAR FROM A SLAM
DUNK IN LIGHT OF A GENERALLY WEAKLY FORCED WARM SECTOR ENVIRONMENT.
HOWEVER...THE POTENTIAL IS CERTAINLY THERE...AND IN LIGHT OF THE
RATHER VOLATILE ENVIRONMENTAL WARM SECTOR CONDITIONS THAT ARE
EXPECTED (SBCAPE 1500-2000 J/KG...DEEP LAYER SHEAR OF 70
KTS)...SUPERCELLS WOULD BE LIKELY...WITH PERHAPS A THREAT FOR AN
ISOLATED TORNADO NEAR THE WARM FRONT.

WEAKENING SURFACE LOW IS EXPECTED TO TRACK NEAR THE NC/VA LINE SAT
NIGHT INTO SUNDAY...WITH TRAILING COLD FRONT MOVING ACROSS THE AREA
DURING THE MORNING INTO THE AFTERNOON. A BIT OF SBCAPE MAY CREEP
INTO THE PIEDMONT AHEAD OF THE FRONT BY EARLY AFTERNOON...WHILE NW
FLOW COULD SUPPORT SHOWER DEVELOPMENT ACROSS THE FAR WESTERN MTNS.
POPS FOR SCATTERED CONVECTION ARE THEREFORE WARRANTED IN MAINLY
THOSE AREAS. THE REMAINDER OF THE PERIOD WILL BE QUIET AND DRY...
WITH TEMPS ABOUT 5 DEGREES BELOW CLIMO.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 145 PM FRIDAY...THE MODEL GUIDANCE HAS CONTINUED THE TREND OF
DELAYING THE ARRIVAL OF THE NEXT SYSTEM DURING THE MIDDLE OF NEXT
WEEK. THE LATEST GFS KEEPS THE UPPER RIDGE AXIS TO THE WEST MONDAY
NIGHT AND DOES NOT MAKE IT INTO THE WESTERN CAROLINAS UNTIL MAYBE
VERY LATE IN THE DAY ON TUESDAY. THE 00Z RUN OF THE ECMWF WAS
SIMILAR IN SHOWING LITTLE SUPPORT OR MOISTURE FOR PRECIP UNTIL MAYBE
LATE TUESDAY AFTERNOON. WITH THAT IN MIND...WILL IMPOSE YET ANOTHER
DELAY WITH THE ARRIVAL OF PRECIP CHANCES FROM THE SOUTHWEST UNTIL
LATE TUESDAY AFTERNOON...AND WILL SLOW THE INCREASE IN PRECIP
CHANCES TUESDAY NIGHT. NOT MUCH IN THE NEW MODEL GUIDANCE TO SUGGEST
ANY CHANGES TO THE FCST...UNLESS THE 12Z RUN OF THE ECMWF TRENDS
FASTER LIKE THE GFS. HOWEVER...IN SPITE OF THE MODEL DIFFERENCES
WITH THE EVOLUTION OF THE UPPER LOW AND TRACK/STRENGTH OF THE
SURFACE LOW MOVING ACROSS THE DEEP SOUTH ON WEDNESDAY AND
THURSDAY... THE WEAKER/FASTER GFS STILL MANAGES TO HOLD ONTO SOME
LIGHT PRECIP ACROSS THE WESTERN CAROLINAS AS ITS SHEARING/POSITIVELY
TILTED UPPER TROF MOVES OVERHEAD THRU THURSDAY EVENING. THUS...FEW
CHANGES WERE MADE. PRECIP PROB WAS KEPT IN THE CHANCE RANGE AND
TEMPS WERE KEPT SEASONALLY COOL...ABOUT 10 DEG BELOW NORMAL. THE
MODEL SOLUTIONS COME INTO AGREEMENT BY THURSDAY NIGHT WITH MOVING
THE PRECIP OUT. FRIDAY SHOULD BE DRY WITH HIGH PRESSURE BUILDING IN
FROM THE WEST AND TEMPS STARTING A REBOUND TOWARD NORMAL.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...HIGH DEBRIS CLOUDS WILL LIKELY INCREASE ACROSS THE NC
PIEDMONT THROUGH SUNRISE. LLVL MOISTURE SHOULD RAPIDLY INCREASE FROM
THE SOUTHWEST DURING THE MID TO LATE MORNING HOURS...RESULTING IN
MVFR CEILINGS AND LIGHT SHRA. CEILINGS WILL CONTINUE TO LOWER INTO
THE AFTERNOON AS LLVL WINDS INCREASES...DEEPENING THE LLVL FORCING.
BASED ON THE TIMING OF THE NAM...SBCAPE AND STEEPENING LAPSE RATES
WILL DEVELOP DURING THE LATE AFTERNOON AND EARLY EVENING. I WILL
HIGHLIGHT THE 22Z TO 1Z WINDOW WITH A PROB30 FOR TSRA. BY LATE
EVENING...FORECAST SOUNDINGS BECOME MOIST THROUGH A DEEP LAYER AND
MODEL CLOUDS ARE EASILY WITHIN IFR. WINDS DURING THE 6Z TAF WILL
REMAIN FROM THE SOUTH-SOUTHWEST...RESULTING FROM THE APPROACH OF A
WELL ORGANIZED SFC LOW OVER KY/TN.

ELSEWHERE...CONDITIONS WILL GENERALLY FOLLOW THE TREND DISCUSSED FOR
CLT ABOVE. HOWEVER...INCREASES IN MOISTURE AND INSTABILITY WILL
REACH KAND SEVERAL HOURS EARLIER THAN KCLT. THE DEEP MOISTURE AND
FORCING WILL SPREAD SW TO NE...REACHING KHKY AROUND THE SAME PERIOD
AS KCLT. KHKY MAY DEVELOP WINDS FROM THE EAST-NORTHEAST AROUND
SUNRISE...PERSISTING THROUGH THE REST OF THE TAF PERIOD.
ELSEWHERE...WINDS WILL REMAIN FROM THE SOUTH-SOUTHWEST.
THUNDERSTORMS SHOULD DEVELOP OVER THE REGION DURING THE LATE
AFTERNOON TO EARLY EVENING PERIOD. THE GREATEST OVERLAP OF SHEAR AND
INSTABILITY WILL GENERALLY OCCUR ALONG AND WEST OF I-26...SUPPORTING
DAMAGING WINDS AND HAIL. I WILL HIGHLIGHT THE PERIOD OF DEEP
CONVECTION WITH A PROB30.

OUTLOOK...A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE MID ATLANTIC
STATES THIS WEEKEND...AND WIDESPREAD RAINFALL MAY SUPPORT
RESTRICTIONS. A COLD FRONT WILL SWEEP ACROSS THE REGION SUNDAY
NIGHT...FOLLOWED BY DRY HIGH PRESSURE THROUGH TUESDAY. ANOTHER LOW
PRESSURE SYSTEM MAY TRACK ACROSS THE DEEP SOUTH WEDNESDAY AND
THURSDAY.

CONFIDENCE TABLE...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       HIGH 100%     MED   79%     MED   72%     HIGH  80%
KGSP       HIGH 100%     MED   68%     HIGH  87%     HIGH  83%
KAVL       HIGH 100%     MED   77%     MED   75%     HIGH 100%
KHKY       HIGH 100%     MED   73%     MED   72%     HIGH  85%
KGMU       HIGH 100%     MED   71%     MED   77%     HIGH  83%
KAND       HIGH 100%     MED   68%     MED   78%     HIGH  96%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...DEO
NEAR TERM...NED
SHORT TERM...JDL
LONG TERM...PM
AVIATION...NED




000
FXUS62 KCAE 250602
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
202 AM EDT SAT APR 25 2015

.SYNOPSIS...
MOISTURE WILL INCREASE TODAY AHEAD OF A WARM FRONT. THIS FRONT
WILL BE A FOCUS FOR SHOWERS AND SOME THUNDERSTORMS SATURDAY. DRIER
WEATHER RETURNS FOR SUNDAY...LASTING INTO MUCH OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CLOUD COVER SHOULD BE ON THE INCREASE LATE TONIGHT AHEAD OF AN
ADVANCING AREA OF LOW PRESSURE. MOISTURE IS ALSO FORECAST TO BE ON
THE INCREASE FROM TOP DOWN AFTER 06Z TONIGHT AS SOUTHWESTERLY
WINDS TRY BRINGING MOISTURE. BUFKIT SOUNDINGS INDICATING PW
VALUES INCREASING FROM AROUND AN INCH AT 06Z TO BETWEEN 1.25 AND
1.5 INCHES BY 12Z. EXPECT A DRY FORECAST THROUGH AT LEAST 06Z
TONIGHT...THEN POPS INCREASING TO CHANCE ACROSS THE WEST TOWARDS
MORNING...AND SLIGHT CHANCE ACROSS THE EAST. OVERNIGHT LOWS ARE
EXPECTED TO BE IN LOWER 50S IN MOST AREAS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
PRECIPITABLE WATER VALUES RAPIDLY INCREASE FROM AROUND A HALF
INCH TO CLOSE TO 1.75 INCHES BY 18Z SATURDAY. FEEL CONFIDENT THERE
WILL BE MEASURABLE RAINFALL ON SATURDAY SO WILL CONTINUE THE
CATEGORICAL POPS AND EXPECT ON AVERAGE AROUND A HALF INCH OR SO
RAINFALL.

CONVECTION IS ANOTHER POTENTIAL ISSUE ON SATURDAY AS THE UPPER
TROUGH AND ATTENDANT SURFACE LOW TRACK EAST ACROSS THE PLAINS INTO
THE MISSISSIPPI VALLEY...STRONG KINEMATIC FIELDS SHIFT OVER THE
FORECAST AREA WITH SOUTHWESTERLY LOW LEVEL JET OF 50-60 KNOTS
COMBINED WITH SOME DIRECTIONAL WIND SHEAR WILL SUPPORT THE THREAT
FOR SEVERE WEATHER AS THE WARM FRONT LIFTS NORTHWARD ACROSS THE
REGION.  INSTABILITY REMAINS AN UNCERTAINTY BUT DEPENDING ON HOW
QUICKLY THE ISENTROPIC LIFT SHIFTS OUT OF THE AREA...LATE AFTERNOON
AND EVENING SATURDAY MAY ALLOW FOR SOME RECOVERY. POSSIBLE
ONGOING CONVECTION MOVING ACROSS THE TENNESSEE VALLEY SATURDAY
MORNING WHICH WILL THEN TRACK EAST- SOUTHEASTWARD INTO OUR REGION
SATURDAY AFTERNOON. SPC HAS EXPANDED THE SLIGHT RISK TO INCLUDE
THE MOST OF THE CWA WITH AN AREA OF ENHANCED RISK ACROSS TN/KY.

SOME LINGERING SHOWERS/STORMS POSSIBLE SATURDAY NIGHT INTO SUNDAY
WITH THE NORTHERN MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS
THE SURFACE LOW SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY
SUNDAY EVENING.  MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS
NOTED ON SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH
CONVECTION SO WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN
MIDLANDS.

TEMPERATURES ON SATURDAY WILL BE LIMITED BY THE CLOUDS AND RAINFALL
FOR MUCH OF THE DAY BUT THERE IS SOME UNCERTAINTY ABOUT SOME
POSSIBLE RECOVERY LATE IN THE DAY AND ENSEMBLE DATA SUGGESTS SOME
UNCERTAINTY BUT WE SHOULD SEE A GRADIENT IN TEMPS FROM THE 60S NORTH
TO 70S SOUTH.  SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND
DOWNSLOPING NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
MEDIUM RANGE MODELS APPEAR TO BE COMING INTO SOMEWHAT BETTER
AGREEMENT WITH THE OVERALL PATTERN NEXT WEEK. ON MON/TUE THE
FORECAST AREA WILL BE BETWEEN THE DEPARTING SYSTEM OFF THE EAST
COAST AND YET ANOTHER SLOW MOVING CLOSED UPPER LOW EJECTING
EASTWARD OUT OF THE SOUTHWESTERN STATES. EXPECT DRY WEATHER AND
BELOW NORMAL TEMPERATURES WITH A PERSISTENT NORTHERLY FLOW AND
SURFACE HIGH PRESSURE RIDGING INTO THE AREA FROM THE NORTH. THE
SOUTHERN STREAM CLOSED LOW WILL BEGIN TO OPEN AND DRIFT EASTWARD
EVENTUALLY PHASING WITH NORTHERN STREAM ENERGY BRINGING UNSETTLED
WEATHER TO OUR AREA TUESDAY INTO THURSDAY. LATEST GFS SHOWS DRY HIGH
PRESSURE BUILDING IN FROM THE WEST FRIDAY. TEMPERATURES GENERALLY
AT OR JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH AROUND 12Z THEN LOWER
CONFIDENCE AS MVFR RESTRICTIONS EXPECTED TO DEVELOP ALL TERMINALS
AS WIDESPREAD RAIN OVERSPREADS THE REGION ASSOCIATED WITH WARM
ADVECTION AS A WARM FRONT LIFTS NORTHWARD. LIGHT RAIN EXPECTED TO
IMPACT THE TERMINALS AFTER 12Z WITH MVFR CIGS/VSBYS SETTING IN
BETWEEN 14Z-16Z. LIGHT SOUTH TO SOUTHEASTERLY WINDS SHOULD
DEVELOP BY 12Z AND GRADUALLY SHIFT TO THE SOUTH AND EVENTUALLY
SOUTHWEST AS A WARM FRONT LIFTS NORTH THROUGH THE REGION THOUGH
THE DAY. SOME CONVECTION WITH STRONG THUNDERSTORMS POSSIBLE AFTER
16Z THROUGH 03Z-06Z TONIGHT BUT TIMING AND LOCATION STILL
UNCERTAIN SO WILL ONLY MENTION RAIN FOR NOW. CIGS SHOULD BECOME
MORE BROKEN OR SCATTERED LATE AFTERNOON AS THE WARM FRONT LIFTS
NORTHWARD BUT TIMING REMAINS UNCERTAIN.

LOW-LEVEL WIND SHEAR MAY BE AN ISSUE BEFORE WARM FRONTAL PASSAGE.
HIGH SHEAR AND INSTABILITY NEAR THE WARM FRONT MAY HELP SUPPORT
SEVERE THUNDERSTORMS WITH DAMAGING WIND AND HAIL SATURDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...SHOWERS AND THUNDERSTORMS WITH
ASSOCIATED RESTRICTIONS WILL BE POSSIBLE INTO SATURDAY EVENING.
BREEZY CONDITIONS POSSIBLE SUNDAY. NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







000
FXUS62 KCAE 250602
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
202 AM EDT SAT APR 25 2015

.SYNOPSIS...
MOISTURE WILL INCREASE TODAY AHEAD OF A WARM FRONT. THIS FRONT
WILL BE A FOCUS FOR SHOWERS AND SOME THUNDERSTORMS SATURDAY. DRIER
WEATHER RETURNS FOR SUNDAY...LASTING INTO MUCH OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CLOUD COVER SHOULD BE ON THE INCREASE LATE TONIGHT AHEAD OF AN
ADVANCING AREA OF LOW PRESSURE. MOISTURE IS ALSO FORECAST TO BE ON
THE INCREASE FROM TOP DOWN AFTER 06Z TONIGHT AS SOUTHWESTERLY
WINDS TRY BRINGING MOISTURE. BUFKIT SOUNDINGS INDICATING PW
VALUES INCREASING FROM AROUND AN INCH AT 06Z TO BETWEEN 1.25 AND
1.5 INCHES BY 12Z. EXPECT A DRY FORECAST THROUGH AT LEAST 06Z
TONIGHT...THEN POPS INCREASING TO CHANCE ACROSS THE WEST TOWARDS
MORNING...AND SLIGHT CHANCE ACROSS THE EAST. OVERNIGHT LOWS ARE
EXPECTED TO BE IN LOWER 50S IN MOST AREAS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
PRECIPITABLE WATER VALUES RAPIDLY INCREASE FROM AROUND A HALF
INCH TO CLOSE TO 1.75 INCHES BY 18Z SATURDAY. FEEL CONFIDENT THERE
WILL BE MEASURABLE RAINFALL ON SATURDAY SO WILL CONTINUE THE
CATEGORICAL POPS AND EXPECT ON AVERAGE AROUND A HALF INCH OR SO
RAINFALL.

CONVECTION IS ANOTHER POTENTIAL ISSUE ON SATURDAY AS THE UPPER
TROUGH AND ATTENDANT SURFACE LOW TRACK EAST ACROSS THE PLAINS INTO
THE MISSISSIPPI VALLEY...STRONG KINEMATIC FIELDS SHIFT OVER THE
FORECAST AREA WITH SOUTHWESTERLY LOW LEVEL JET OF 50-60 KNOTS
COMBINED WITH SOME DIRECTIONAL WIND SHEAR WILL SUPPORT THE THREAT
FOR SEVERE WEATHER AS THE WARM FRONT LIFTS NORTHWARD ACROSS THE
REGION.  INSTABILITY REMAINS AN UNCERTAINTY BUT DEPENDING ON HOW
QUICKLY THE ISENTROPIC LIFT SHIFTS OUT OF THE AREA...LATE AFTERNOON
AND EVENING SATURDAY MAY ALLOW FOR SOME RECOVERY. POSSIBLE
ONGOING CONVECTION MOVING ACROSS THE TENNESSEE VALLEY SATURDAY
MORNING WHICH WILL THEN TRACK EAST- SOUTHEASTWARD INTO OUR REGION
SATURDAY AFTERNOON. SPC HAS EXPANDED THE SLIGHT RISK TO INCLUDE
THE MOST OF THE CWA WITH AN AREA OF ENHANCED RISK ACROSS TN/KY.

SOME LINGERING SHOWERS/STORMS POSSIBLE SATURDAY NIGHT INTO SUNDAY
WITH THE NORTHERN MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS
THE SURFACE LOW SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY
SUNDAY EVENING.  MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS
NOTED ON SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH
CONVECTION SO WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN
MIDLANDS.

TEMPERATURES ON SATURDAY WILL BE LIMITED BY THE CLOUDS AND RAINFALL
FOR MUCH OF THE DAY BUT THERE IS SOME UNCERTAINTY ABOUT SOME
POSSIBLE RECOVERY LATE IN THE DAY AND ENSEMBLE DATA SUGGESTS SOME
UNCERTAINTY BUT WE SHOULD SEE A GRADIENT IN TEMPS FROM THE 60S NORTH
TO 70S SOUTH.  SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND
DOWNSLOPING NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
MEDIUM RANGE MODELS APPEAR TO BE COMING INTO SOMEWHAT BETTER
AGREEMENT WITH THE OVERALL PATTERN NEXT WEEK. ON MON/TUE THE
FORECAST AREA WILL BE BETWEEN THE DEPARTING SYSTEM OFF THE EAST
COAST AND YET ANOTHER SLOW MOVING CLOSED UPPER LOW EJECTING
EASTWARD OUT OF THE SOUTHWESTERN STATES. EXPECT DRY WEATHER AND
BELOW NORMAL TEMPERATURES WITH A PERSISTENT NORTHERLY FLOW AND
SURFACE HIGH PRESSURE RIDGING INTO THE AREA FROM THE NORTH. THE
SOUTHERN STREAM CLOSED LOW WILL BEGIN TO OPEN AND DRIFT EASTWARD
EVENTUALLY PHASING WITH NORTHERN STREAM ENERGY BRINGING UNSETTLED
WEATHER TO OUR AREA TUESDAY INTO THURSDAY. LATEST GFS SHOWS DRY HIGH
PRESSURE BUILDING IN FROM THE WEST FRIDAY. TEMPERATURES GENERALLY
AT OR JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH AROUND 12Z THEN LOWER
CONFIDENCE AS MVFR RESTRICTIONS EXPECTED TO DEVELOP ALL TERMINALS
AS WIDESPREAD RAIN OVERSPREADS THE REGION ASSOCIATED WITH WARM
ADVECTION AS A WARM FRONT LIFTS NORTHWARD. LIGHT RAIN EXPECTED TO
IMPACT THE TERMINALS AFTER 12Z WITH MVFR CIGS/VSBYS SETTING IN
BETWEEN 14Z-16Z. LIGHT SOUTH TO SOUTHEASTERLY WINDS SHOULD
DEVELOP BY 12Z AND GRADUALLY SHIFT TO THE SOUTH AND EVENTUALLY
SOUTHWEST AS A WARM FRONT LIFTS NORTH THROUGH THE REGION THOUGH
THE DAY. SOME CONVECTION WITH STRONG THUNDERSTORMS POSSIBLE AFTER
16Z THROUGH 03Z-06Z TONIGHT BUT TIMING AND LOCATION STILL
UNCERTAIN SO WILL ONLY MENTION RAIN FOR NOW. CIGS SHOULD BECOME
MORE BROKEN OR SCATTERED LATE AFTERNOON AS THE WARM FRONT LIFTS
NORTHWARD BUT TIMING REMAINS UNCERTAIN.

LOW-LEVEL WIND SHEAR MAY BE AN ISSUE BEFORE WARM FRONTAL PASSAGE.
HIGH SHEAR AND INSTABILITY NEAR THE WARM FRONT MAY HELP SUPPORT
SEVERE THUNDERSTORMS WITH DAMAGING WIND AND HAIL SATURDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...SHOWERS AND THUNDERSTORMS WITH
ASSOCIATED RESTRICTIONS WILL BE POSSIBLE INTO SATURDAY EVENING.
BREEZY CONDITIONS POSSIBLE SUNDAY. NO SIGNIFICANT IMPACTS EXPECTED
MONDAY AND TUESDAY. AN APPROACHING WARM FRONT MAY RESULT IN
WIDESPREAD RESTRICTIONS WEDNESDAY.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$






000
FXUS62 KCAE 250602
AFDCAE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
202 AM EDT SAT APR 25 2015

.SYNOPSIS...
MOISTURE WILL INCREASE TODAY AHEAD OF A WARM FRONT. THIS FRONT
WILL BE A FOCUS FOR SHOWERS AND SOME THUNDERSTORMS SATURDAY. DRIER
WEATHER RETURNS FOR SUNDAY...LASTING INTO MUCH OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CLOUD COVER SHOULD BE ON THE INCREASE LATE TONIGHT AHEAD OF AN
ADVANCING AREA OF LOW PRESSURE. MOISTURE IS ALSO FORECAST TO BE ON
THE INCREASE FROM TOP DOWN AFTER 06Z TONIGHT AS SOUTHWESTERLY
WINDS TRY BRINGING MOISTURE. BUFKIT SOUNDINGS INDICATING PW
VALUES INCREASING FROM AROUND AN INCH AT 06Z TO BETWEEN 1.25 AND
1.5 INCHES BY 12Z. EXPECT A DRY FORECAST THROUGH AT LEAST 06Z
TONIGHT...THEN POPS INCREASING TO CHANCE ACROSS THE WEST TOWARDS
MORNING...AND SLIGHT CHANCE ACROSS THE EAST. OVERNIGHT LOWS ARE
EXPECTED TO BE IN LOWER 50S IN MOST AREAS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
PRECIPITABLE WATER VALUES RAPIDLY INCREASE FROM AROUND A HALF
INCH TO CLOSE TO 1.75 INCHES BY 18Z SATURDAY. FEEL CONFIDENT THERE
WILL BE MEASURABLE RAINFALL ON SATURDAY SO WILL CONTINUE THE
CATEGORICAL POPS AND EXPECT ON AVERAGE AROUND A HALF INCH OR SO
RAINFALL.

CONVECTION IS ANOTHER POTENTIAL ISSUE ON SATURDAY AS THE UPPER
TROUGH AND ATTENDANT SURFACE LOW TRACK EAST ACROSS THE PLAINS INTO
THE MISSISSIPPI VALLEY...STRONG KINEMATIC FIELDS SHIFT OVER THE
FORECAST AREA WITH SOUTHWESTERLY LOW LEVEL JET OF 50-60 KNOTS
COMBINED WITH SOME DIRECTIONAL WIND SHEAR WILL SUPPORT THE THREAT
FOR SEVERE WEATHER AS THE WARM FRONT LIFTS NORTHWARD ACROSS THE
REGION.  INSTABILITY REMAINS AN UNCERTAINTY BUT DEPENDING ON HOW
QUICKLY THE ISENTROPIC LIFT SHIFTS OUT OF THE AREA...LATE AFTERNOON
AND EVENING SATURDAY MAY ALLOW FOR SOME RECOVERY. POSSIBLE
ONGOING CONVECTION MOVING ACROSS THE TENNESSEE VALLEY SATURDAY
MORNING WHICH WILL THEN TRACK EAST- SOUTHEASTWARD INTO OUR REGION
SATURDAY AFTERNOON. SPC HAS EXPANDED THE SLIGHT RISK TO INCLUDE
THE MOST OF THE CWA WITH AN AREA OF ENHANCED RISK ACROSS TN/KY.

SOME LINGERING SHOWERS/STORMS POSSIBLE SATURDAY NIGHT INTO SUNDAY
WITH THE NORTHERN MIDLANDS LIKELY TO BE MORE FAVORED ON SUNDAY AS
THE SURFACE LOW SINKS SOUTHEASTWARD ACROSS VA/NC AND OFFSHORE BY
SUNDAY EVENING.  MODERATE TO STRONG INSTABILITY AND COLD 500MB TEMPS
NOTED ON SUNDAY BUT MOISTURE MAY BE LACKING TO SUPPORT MUCH
CONVECTION SO WILL CONTINUE WITH LOW CHANCE POPS ACROSS THE NORTHERN
MIDLANDS.

TEMPERATURES ON SATURDAY WILL BE LIMITED BY THE CLOUDS AND RAINFALL
FOR MUCH OF THE DAY BUT THERE IS SOME UNCERTAINTY ABOUT SOME
POSSIBLE RECOVERY LATE IN THE DAY AND ENSEMBLE DATA SUGGESTS SOME
UNCERTAINTY BUT WE SHOULD SEE A GRADIENT IN TEMPS FROM THE 60S NORTH
TO 70S SOUTH.  SUNDAY LOOKS TO BE A WARM DAY WITH SOME SUNSHINE AND
DOWNSLOPING NORTHWESTERLY FLOW WITH HIGHS BACK INTO THE 80S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
MEDIUM RANGE MODELS APPEAR TO BE COMING INTO SOMEWHAT BETTER
AGREEMENT WITH THE OVERALL PATTERN NEXT WEEK. ON MON/TUE THE
FORECAST AREA WILL BE BETWEEN THE DEPARTING SYSTEM OFF THE EAST
COAST AND YET ANOTHER SLOW MOVING CLOSED UPPER LOW EJECTING
EASTWARD OUT OF THE SOUTHWESTERN STATES. EXPECT DRY WEATHER AND
BELOW NORMAL TEMPERATURES WITH A PERSISTENT NORTHERLY FLOW AND
SURFACE HIGH PRESSURE RIDGING INTO THE AREA FROM THE NORTH. THE
SOUTHERN STREAM CLOSED LOW WILL BEGIN TO OPEN AND DRIFT EASTWARD
EVENTUALLY PHASING WITH NORTHERN STREAM ENERGY BRINGING UNSETTLED
WEATHER TO OUR AREA TUESDAY INTO THURSDAY. LATEST GFS SHOWS DRY HIGH
PRESSURE BUILDING IN FROM THE WEST FRIDAY. TEMPERATURES GENERALLY
AT OR JUST BELOW NORMAL THROUGH THE EXTENDED PERIOD.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH AROUND 12Z THEN LOWER
CONFIDENCE AS MVFR RESTRICTIONS EXPECTED TO DEVELOP ALL TERMINALS
AS WIDESPREAD RAIN OVERSPREADS THE REGION ASSOCIATED WITH WARM
ADVECTION AS A WARM FRONT LIFTS NORTHWARD. LIGHT RAIN EXPECTED TO
IMPACT THE TERMINALS AFTER 12Z WITH MVFR CIGS/VSBYS SETTING IN
BETWEEN 14Z-16Z. LIGHT SOUTH TO SOUTHEASTE